delivered the opinion of the Court.
On 22 March 1971 at a bench trial in the Circuit Court for Frederick County Ronnie Smith was convicted of robbery and sentenced to 6 years.*. 1 The judgment was affirmed on appeal. Smith, et al. v. State, No. 242, September Term, 1971, filed 22 November 1971, unreported, cert. denied, 264 Md. 751.
*620On 23 March 1971 the trial court ordered the Commissioner of Correction to deliver Ronnie into the custody of the Director of Patuxent Institution for examination and evaluation as a possible defective delinquent. Code, Art. 31B, § 6 (b). Ronnie arrived at Patuxent on 25 May 1971. He refused to submit to examination or to participate in testing procedures. Because of his failure to cooperate, the Patuxent staff indicated about 30 June 1972 that they were unable to evaluate him. In July 1972 Ronnie was one of a number of Patuxent patients who petitioned the Circuit Court for Montgomery County for the issuance of a writ of habeas corpus, seeking release from the Institution because no evaluation of them had been made within six months of their arrival pursuant to Code, Art. 31B, § 7 (a). On 14 August Patuxent filed a report in the Circuit Court for Frederick County giving the opinion that Ronnie met the definition of a defective delinquent. On 24 August the Circuit Court for Frederick County summoned Ronnie before it and advised him of the substance of the report. It informed him that there would be a hearing to determine whether he was a defective delinquent and that counsel would be appointed to represent him. Art. 31B, § 8 (a).
On 4 October 1972, the Circuit Court for Montgomery County, Shearin, J., acting in the habeas corpus proceeding, concluded that the reporting provisions of Art. 3lB, § 7 (a)2 were mandatory and hence Ronnie was entitled to be released frqm Patuxent and transferred to the Division of Correction for the service of his original sentence.3 It issued an order to that effect. The Director took a timely appeal *621from the order to the Court of Special Appeals. The Court of Appeals granted certiorari before decision by us. It reversed the order. Director v. Cash, 269 Md. 331, decided 14 June 1973. Ronnie was returned to Patuxent. On 8 October 1973 Patuxent resubmitted the evaluation of him made under date of 14 August 1972. On 23 October 1973 Ronnie was again summoned before the Circuit Court for Frederick County and advised pursuant to Art. 31B, § 8 (a). Hearing for determination of defective delinquency was scheduled for 20 November. On 31 October Ronnie filed a motion to dismiss and on 5 November moved for permission to employ a private psychiatrist to examine him pursuant to Art. 31B, § 7 (b), and for a postponement of the hearing pending the examination. The motions were heard on 8 November. On 4 February 1974 the court denied the motion to dismiss, and granted the motion to employ a private psychiatrist and postpone the hearing. In September 1974 Ronnie was informed that the hearing was set for 18 October. He again moved to dismiss the action. The motion was denied on 18 October and the hearing proceeded before a jury. The jury determined that he was a defective delinquent and by order issued the same date Ronnie was committed to Patuxent for an indeterminate period. Application for leave to appeal was timely filed on 18 November. Art. 31B, § 11; Maryland Rule 1094 a l.4 We granted the application on 21 January 1975 and ordered the case transferred to our regular appeal docket. Art. 31B, § 11; Rule 1094 c. Briefs were filed. Oral argument was made on 23 June 1975.
QUESTIONS PRESENTED
Ronnie presents three questions for determination:
I. “Whether the delay between [his] commitment to Patuxent and his trial was so great that it denied [him] due process of law.”
II. “Whether the lower Court erred in refusing to instruct the jury that the experts’ finding of *622defective delinquency requires a ‘diagnosis and prognosis using acceptable and recognized medical and psychiatric procedure’.”
III. “Whether the Court erred in failing to grant [his] timely motion for a mistrial during the testimony of Dr. Harold Boslow.”
I
The first question concerns the propriety of the denial of the motions made to dismiss the defective delinquency action with prejudice. Ronnie alleges that the delay between the time he arrived at Patuxent and the time he was evaluated to be a defective delinquent, and between the time he was so evaluated and the time of the defective delinquency hearing, denied him due process of law.
The Lapse of Time between the Arrival at Patuxent and, the Evaluation
We note first that the six months designation for the filing of the. written report of the examination of a possible defective delinquent is directory and not mandatory. Director v. Cash, supra, at 341-345. Therefore, Ronnie was not entitled to have the report of the examination of him filed within six months of his arrival at Patuxent as a matter of statutory right.
Ronnie’s argument goes this way. State v. Musgrove, 241 Md. 521, held, at 532, that despite the provisions as to time for reporting in § 7 (a), “the order of a court referring a person to Patuxent for an examination until such time as the procedures for determining whether or not such person is a defective delinquent have been completed could not be defeated by the refusal of such person to submit to the examination required by § 7 (a) if the Patuxent staff cannot make its determination without it.” The Court found it “clear. that a person cannot complain of the action, or iiiaction, of others when he is the cause of the delay that ensues.” Pointing to the phrase “if the Patuxent staff cannot make its determination without it” as a proviso to the rule *623that a person may not defeat the purpose of the statute by refusing to submit to examination, Ronnie cites the express approval of the Court in Roberts v. Director, 226 Md. 643, 650, to the assertion that a person is entitled to have the issue of defective delinquency tried within a reasonable time after the Institution has had reasonable time to make its findings. He refers to the statement in McNeil v. Director, 407 U. S. 245, 251-252, after holding, at 250, that it is a denial of due process to hold a person on the basis of an ex parte order committing him for observation, that “if the Patuxent staff was prepared to conclude, on the basis of petitioner’s silence and their observations of him over the years, that petitioner is a defective delinquent, then it is not true that he has prevented them from evaluating him. On that theory, they have long been ready to make their report to the Court, and the hearing on defective delinquency could have gone forward.” (emphasis added by Ronnie). Due process, the Court continued, requires that the nature and duration of commitment bear some reasonable relation to the purpose for which the individual is committed. It is Ronnie’s view that Patuxent has answered the question whether the lapse of time between his arrival at the Institution and the evaluation report was reasonable by filing a report despite the refusal of him to cooperate. He asserts: “Patuxent has taken itself out from under the protective umbrella of Musgrove, for Patuxent has admitted that, as to [him], the Patuxent staff could make its determination without a personal examination. Therefore the ‘non-cooperation’ was irrelevant to their ability to make such an evaluation.” Thus, the failure to evaluate him for some 15 months, he concludes, was unreasonable and a denial of due process.
We find the answer to this argument in Cash. As we have noted, Ronnie was the petitioner in one of the cases before the Court in Cash. The Court found McNeil clearly distinguishable from the cases before it and saw indication in McNeil that the decision was to be narrowly applied. 269 Md. at 345. “We do not consider any of the petitions filed in Cash to be within the holding of the Supreme Court in McNeil and, further, we do not perceive any holding in *624 McNeil that our opinion in Musgrove is impaired. Indeed, in McNeil, the Supreme Court in Note 2 of its opinion cites Musgrove and Mullen v. Director, 6 Md. App. 120, 250 A. 2d 281 (1969), applying Musgrove for the proposition that the Maryland Courts have construed § 7 (a) ‘to permit extension of the allowable time ... in the case of a noncooperative defendant who resists examination.’ There is no suggestion that this was unconstitutional or otherwise improper.” Id. at 349. The Court specifically approved the procedure followed with regard to Ronnie, id. at 347:
“After the decision by the Supreme Court in McNeil on June 19, 1972, the staff was faced with the problem that an undiagnosed person would be released when his sentence expired. After consultation with the Patuxent Board and with counsel, the staff attempted, where possible, to diagnose individuals referred for examination who had declined to cooperate in the examination process on the bases of historical data in the file of each individual. Dr. Boslow further testified, in effect, that he and the staff prefer not to make a diagnosis without a personal interview, but that such a diagnosis would be ‘valid’ in the absence of a showing of an intentional and deliberate designation on the part of the officials of Patuxent to postpone the diagnosis for an unreasonable time (and there is no such evidence in the present cases). The procedure presently followed by the Patuxent officials is proper in accordance with our opinion in Musgrove.”5
*625In the light of the Court of Appeals opinions that the procedure followed with respect to Ronnie was proper, we hold that he was not denied due process of law thereby.
The Lapse of Time between the Report of Examination and the Date of the Hearing
The report of examination opining that Ronnie was a defective delinquent was first filed on 14 August 1972; the hearing to determine defective delinquency was on 18 October 1974. Art 31B, § 8 deals with defective delinquency hearings. If the report of the Institution states that a person is a defective delinquent, the court shall forthwith summon the person before it. It shall advise him of the substance of the report, of the pendency of a hearing, and of his right to be represented by counsel of his choice or by competent counsel appointed by the court. Subsection (a). “Unless appearance of counsel chosen by the person is entered within twenty days following the proceeding set forth in subsection (a) hereof, the court shall appoint counsel to represent the person.” Subsection (b). “The hearing for determination of defective delinquency shall be held no less than thirty days following designation of counsel, unless acceleration of the time is requested by the person or his counsel.” Subsection (c).6
In Marsh v. State, 22 Md. App. 173, 181, we found it clear that § 8 mandates arraignment, appointment of counsel, and hearing upon receipt by the court of a report from Patuxent that an inmate is a defective delinquent. We held, at 182, that “§ 8 becomes effective whenever Patuxent’s written report commanded by § 7 (a) declares that a patient is a defective delinquent.” We observed: “Upon the filing of such a report the patient named therein forthwith is entitled to the rights granted by subsections (b) and (c) of § 8. Under such circumstances, those rights may not be deferred because of an alleged failure of the inmate to submit to personal examinations.” Id.
Here there was compliance with the provisions of § 8 (b). *626Ten days after the report of Patuxent was filed in the Circuit Court for Frederick County Ronnie was brought before the court and advised pursuant to the statute. On 8 October 1973, when Patuxent resubmitted the report, he was again summoned before the court and so advised.
Section 8 (c) does not specify a maximum time within which a hearing must be held. It prohibits a hearing within 30 days of the designation of counsel unless the person believed to be a defective delinquent or his counsel requests an earlier hearing. No such request was made here. In fact, when Ronnie appeared before the Circuit Court for Frederick County on 24 August 1972 to be advised pursuant to § 8 (b), he said he had counsel, and asked how Patuxent could find him to be a defective delinquent without interviewing him. He inquired about the habeas corpus proceeding pending in the Circuit Court for Montgomery County. When told by the court that the hearing to determine the question of his defective delinquency would be a maximum of 50 days hence,7 8he asked if he could get it postponed. Several times thereafter during the course of the hearing he said he wanted a postponement of the defective delinquency hearing.
We see nothing unreasonable in continuing the defective delinquency proceedings until the final disposition, at least in the Maryland courts, of the habeas corpus action instituted by Ronnie in Cash? Obviously, had the order of the Circuit Court for Montgomery County been upheld, the question of defective delinquency vel non would have been moot. We note that under the order issued in that proceeding Ronnie was removed from Patuxent, apparently *627in October 1972, to the custody of the Division of Correction and not returned to Patuxent until the end of June 1973.
The court below found that three months were allowed after Ronnie’s return to Patuxent to ascertain if he would then cooperate in the examination procedures. When it was certain that he would not, the Institution, on 8 October 1973, resubmitted its evaluation report of 4 August 1972 to the Circuit Court for Frederick County.9 Ronnie was then forthwith, on 23 October, summoned before the court and advised pursuant to Art. 31B, § 8 la). On 5 November 1973, through his counsel, he filed a written motion for a continuance of the hearing. He stated that he was “entitled to examination by a psychiatrist of his own choosing, however because of the short notice of trial the psychiatrist which the Defendant has chosen to examine him is unable to make the examination, review the records and present the testimony to the Court on such short notice. The Defendant reserves his right to proceed on the Motion to Dismiss and still requests a hearing on that Motion be set.” The hearing on the Motion to Dismiss was held on 4 February 1974 and denied. Patently, it was proper not to act on the motion to appoint a private psychiatrist until the determination of the motion to dismiss the defective delinquency action. An order granting permission to have a private psychiatrist examine Ronnie was issued the same day the motion to dismiss was *628denied. Brian Crowley, M.D. was appointed by the court as the private psychiatrist to examine Ronnie “for the purposes of determining whether he is a defective delinquent.. . .” It was brought out at the trial on 18 October 1974 that Dr. Crowley examined Ronnie on 26 February 1974 and submitted a report dated 1 October 1974.10
Under the particular facts and circumstances surrounding the delay in holding the hearing to determine Ronnie’s defective delinquency, we see no denial of due process of law. We hold that the court did not err in denying the motion to dismiss the proceeding.
II
Ronnie filed with the court proposed instructions, Maryland Rule 554 a, which included this one as #3:
“The finding of defective delinquency must be based on medical and psychiatric evaluation and depends on a diagnosis and prognosis, using acceptable and recognized medical and psychiatric procedure. In evaluating the testimony of witnesses you may consider the procedure used and the means chosen by each of the experts to reach the opinion given.”
He claims that the court refused to give the instruction as proposed and that the refusal to do so was prejudicial error.
Rule 554 b 1 permits the court to instruct the jury upon the law by granting requested instructions or by giving instructions of its own, or by several or all of those methods. It need not grant any requested instruction, even if proper, if the matter is fairly covered by instructions actually given. A party aggrieved by any portion of an instruction given, or by the failure to give any instruction, must, before the jury *629retires to consider its verdict, make objection “stating distinctly the portion or omission, or failure to instruct to which he objects and the ground of his objection.” Rule 554 d. Upon appeal a party assigning error in the instructions shall be restricted to “(1) particular portion of the instructions given or the particular omission therefrom or the particular failure to instruct distinctly objected to before the jury retired and (2) the grounds of objection distinctly stated at the time, and no errors or assignments of error in the instructions shall be considered by the appellate court.” Rule 554 e.
After the court charged the jury here, counsel were given the opportunity to make objection in open court out of the presence of the jury as provided by Rule 554 d. Ronnie’s counsel requested that his proposed instruction 5 be given.11 The judge explained that he had covered it in the instructions given. Defense counsel said: “All right, Your Honor, I stand corrected and I’m sorry for the exception.” He withdrew the objection and declared that he had no other objections. Therefore, the assignment of error raised on appeal may not be considered by us.
Ill
Ronnie claims that the court below erred in denying his motion for a mistrial. The motion was made out of the presence of the jury during the cross-examination of Dr. Harold Boslow, Director of Patuxent Institution, called as a witness by the State. Dr. Boslow stated that it was his opinion that Ronnie was a defective delinquent, but that it was not based on “personal knowledge as to the young man” because Ronnie “wouldn’t talk to anybody.” The witness was requested to give his “professional opinion as to the propriety and feasibility of an opinion, within the defective *630delinquency context, of rendering such an opinion without a personal interview as a psychiatrist.” He replied:
“I don’t think it’s desirable, but it’s the only thing we can do. I think that in view of the patient’s persistent refusal to see either psychiatrist, psychologist or social worker, and the Court’s pressing us to produce a document, we produced a document. I don’t think it’s desirable, but I think that it’s a good opinion and it’s the best that we can offer under the circumstances.”
He was reminded by defense counsel that he was asked that exact question before in another case and that he had answered:
“I think it is non-valid, superficial and unethical and impossible.”
Dr. Boslow attempted to explain. The transcript reads:
“A Impossible from the viewpoint of giving a definitive diagnosis; but if we have to give a report to the Court and the Court presses us, then I would do this. This was —
Q Would you give an unethical report—
A Wait a minute, you’re asking the question. You’re asking for two levels of responsibility. It’s all right for your client to refuse to take—
MR. DEUTSCHMAN [Defense Counsel]: Your Honor, this is going beyond the scope of the question.
THE COURT: I think he has a right to explain his ansjwer, and I will overrule the objection. You may answer.
WITNESS: You say your client has a right to refuse to be examined, and —
MR. DEUTSCHMAN: I haven’t said anything, Doctor.
*631WITNESS: This is — this is what you’re implying — don’t play games with me.
MR. DEUTSCHMAN: Your Honor, I object to the witness going beyond the scope of the question.
THE COURT: He’s trying to explain his answer and that’s perfectly permissible, and I’m not going to rule on it any more times. You may answer, Doctor.
WITNESS: Your client refuses to take the examination. You say that’s all right. We don’t have anything to offer the Court except our review of his history. Now, my experience with twenty years in this particular situation, and more before that, indicates to me that this man’s behavior in the community and his entire life history indicate that he is dangerous. I have nothing else to go on. If you want your client to have a fair shake, advise your client to take the examinations.”
At this point defense counsel asked for permission to approach the bench and moved for a mistrial.
“THE COURT: On what basis?
MR. DEUTSCHMAN: On the basis of the fact that I asked the witness a question and the Court permitted the witness to continue on a matter which is totally irrelevant to the question asked, making insinuations of — that are not matters of fact and have nothing to do with the question before the Court.
THE COURT: I agree, the answer was not responsive. I overruled your objection because I thought the Doctor was going to explain his answer, which I think he had a perfect right to do. However, when he says if you want to have your client have a fair shake, or whatever, that aspect of it, I think that’s improper and I will instruct the jury to *632disregard that aspect, but I will overrule your motion for a mistrial.”
The court told the jury:
Ladies and gentlemen of the jury, I think that the last statement of the Doctor concerning Mr. Smith was improper and was not responsive to the . . . question; and the jury will disregard that aspect and strike that from your minds.”
The hearing continued.
In Quecedo v. DeVries, 22 Md. App. 58, 68, we repeated what we said in Baldwin v. State, 5 Md. App. 22, 28:
“The granting of a mistrial is an exercise which rests within the discretion of the trial judge. A mistrial should be granted only where plain and obvious reasons exist, upon the greatest caution and under urgent circumstances. Where, in the exercise of this discretion, the trial court refuses to grant a mistrial, such a decision will not be disturbed on appeal without giving full regard to the fact ‘that the trial court is in an advantageous position to judge the question of prejudice, and its decision with reference thereto should not be reversed unless it is clear that there was prejudice.’ Carroll v. State, 3 Md. App 50, 53, 237 A. 2d 535, 538 (1968) quoting Cook v. State, 225 Md. 603, 610, 171 A. 2d 460, 463, cert. den. 368 U. S. 970, 82 S. Ct. 445, 7 L.Ed.2d 398 (1961).”
In view of the curative instruction here, we see no abuse of discretion by the court below in refusing to grant a mistrial. See Wilhelm v. State, 272 Md. 404, 423-424.
Order of 18 October 1974 committing appellant to the jurisdiction of the Patuxent Institution for an indeterminate period affirmed.