of section 183 (3) Evidence Act; the charge itself was not laid under section 218 or 221 Criminal Code and at the time the incident occurred she was 11 years old but was 13 years of age at the time she testified. See: Okoyomon v. State (1973) 1 All NLR (Pt.1) 16; Sambo v. State (1993) 6 NWLR (pt.300) 399. It is also not the law that corroboration is required as a matter of law where a child whose evidence has been received even under oath is the accuser. The case of Akpan v. State (1967) NWLR 185 cited in Shazali v. State (1988) 5 NWLR (pt. 93) 164 did not lay down such a principle. Lewis J.S.C. in Akpan v. State supra at page 188 explained the statement of the law credited to Goddard L.C.J. in R. V Mitchell 36 Cr. App. R. 78 and R. v. Campbell (1956) 2 QB 432 thus:"In our view when Goddard L.C.J. used the word 'should' in the context of the last case cited, he must be taken to have meant that it was a desirable practice that this should be done, not that it was a requirement so that if it was not done the appeal court must allow the appeal." I will agree with the stand taken by learned counsel for the respondent that corroboration is desirable in the instant case and not that it must be provided as a matter of law for the reasons already stated. It is necessary to examine the evidence proffered by the prosecution to see if the desired corroboration of the evidence of PW2 can be found. The 1st PW; Dr. Suleman Abu who examined PW2 said that she told him that somebody forcefully had sex with her. He stated in his evidence that "on examination, the vagina was very tender with some whitish brown discharge. The cervix and fornice were purplish blue on the mucosa, due to traumatic inflammation. I tried a swab for the vagina for examination. This showed a group of bacteria called staphylococcus area and a few yeast cells." He then formed the opinion that the girl had forceful penetration of the genital tract associated with attempted strangulation. He admitted under cross-examination that the appellant was not taken to him for examination. Learned counsel for the appellant has submitted following Okoyomon v. State supra that the prosecution had not established that the accused did have carnal knowledge of the prosecutrix in the sense that there had been penetration as required by section 299 of the Criminal Code. I agree with this submission. The finding made by P.W.1 did not link the appellant directly with the condition of PW2's private part. If the appellant had been examined, this would have confirmed if he had a similar disease as found with PW2. I agree with appellant's counsel's submission that for the medical officer's evidence to qualify as corroboration of the fact that the appellant penetrated the vagina of the prosecutrix, it must point directly and irreversibly to the appellant. The nature of a corroborative evidence capable of grounding conviction on a charge of rape is that it must be cogent,