889.) In the instant case, the prosecution did not produce a birth certificate to prove the victim’s age. Instead, it relied on sonic other two pieces of evidence, that is to say, Dr. Kalyemenya’s evidence and Yerina Nakyejwe’s evidence, Dr. Kalyemenya examined the victim on 20 July 2001. He formed the opinion that the victim was 16 years old at that time, (See Exh. FL) He based his opinion, among other things, on the fact that the victim had a set of 2$ teeth, According to him only persons below the age of 18 years have that number of teeth, Persons of 18 years and above have a dental formula of 32 teeth, On her part Nakyejwe, who is the victim’s mother, testified that her daughter Sarah was born in 1985. The accused did not shake or contradict the above evidence. In essence, Nakyejwe’s evidence and Dr. Kalyemenya’s evidence was agreed that Sarah was 16 years of age at the time of the offence in question The assessors, who had opportunity to observe the victim when she gave evidence in Court, also, shared that opinion. In the circumstances, Court is of the opinion that the prosecution succeeded in proving, beyond reasonable doubt, that Sarah Nampa was a girl under the age of 18 years on 18th July 2001. With regard to the second ingredient, that is to say, that the victim had sexual intercourse on 18th July 2001. first of all Court must define what, in law, amounts to sexual intercourse, According to Archibald on Criminal Pleading 30th Edition page 1124 at paragraph 2873, sexual intercourse is complete when a male sexual organ penetrates a Female sexual organ; and the slightest penetration is enough. Our courts have, time and again, applied that principle with approval. (See Hahyarimana Ronald v Uganda (CA) Criminal Appeal No. 1 of 98; and Didas v Uganda (CA) Criminal Appeal No. 35 of I997) In the instant case, the prosecution relied solely on the evidence of Sarah to prove that she had sexual intercourse on 18th July 2001. In her testimony Sarah insisted that she had sexual intercourse on the day in question. She explained that the act took place at Kyebando where someone took her into a house, removed her knickers and had sexual intercourse with her by way of inserting his male sexual organ into her female sexual organ. Despite vigorous cross-examination Sarah firmly stuck to that story. The defence case was a denial that the accused committed the offence in question.