We have noted that unusual boys may ejaculate as early as eight years of age. As we may expect, there are surprisingly late upper extremes as well.

There are of course sad cases of life-long ejaculatory impotence. But assuming that most men start ejaculating at some time in their lives what is the latest age for such a commencement? According to Kinsey the latest ages of first ejaculation reliably recorded "are 21 for two apparently healthy males, 24 for a religiously inhibited individual, and 22 and 24 for two males with hormonal deficiencies."

Human sperm were first discovered by a student of Antonij van Leeuwenhoek in 1677 in the city of Delft. The name of the student is not known for certain: he is variously written up as Ludwig Hamm, van Hamm or von Hammen. According to some writers he is a Dutchman, to others a German. One day he brought to the acknowledged master of microscopy, Leeuwenhoek, a bottle containing semen and pointed out that small animals could be seen moving about in the ejaculate.

The earliest ejaculation remembered by any of the "apparently normal males" surveyed by Kinsey was at the age of eight: this age was noted by three males.

In the average human ejaculate there are several hundred million live and mobile sperm. The older a man gets the fewer sperm he manages to manufacture. By the age of eighty or ninety most men are infertile, though they often have enjoyable sex lives.

In a few relatively isolated communities old men appear to sire offspring with great success, a facility that appears to be associated with great longevity - as, for instance, in Georgia in the USSR and in the valley of Vilcabamba in Ecuador. I have yet to see studies of fertility in old men in these communities.

There is dispute as to whether premature ejaculation should be counted an instance of impotence. It is evidently a sign of male inadequacy and is commoner than, say, erectile impotence.

Kinsey however refused to recognise premature ejaculation as a problem for the male, though it evidently caused distress to a woman. Kinsey noted, in justification, that many mammals ejaculate very rapidly.

Various extremely unusual masturbatory techniques have been used by both men and women to achieve orgasm, and, with men ejaculation.

It is a commonplace that fantasy accompanied by digital manipulation of the penis, can produce ejaculation in the majority of men. A small number, however, can accomplish ejaculation by means of fantasy alone.

This, we may assume, is yet another one for a future Sex Olympics. Considering the amount of masturbation that goes on there must be considerable volume of semen discharged in the absence of a convenient vaginal receptacle. The distances the seminal fluid achieves before being arrested in flight must surely vary. I have seen very little documentation on this.

Penis size has always worried human males more than ejaculate volume - though if more men read pornography they may enlarge their ambitions.

The first clinical definition appears in Copland's "Dictionary of Practical Medicine" in editions between 1833 and 1858. Later Strauss (1950) defines it as "the inability to perform the sexual act". Ernest Jones (1918) declares it is "the complete or incomplete inability satisfactorily to carry out heterosexual coitus per vaginam. Satisfactorily means adequate erection, time and control of ejaculation."

Frequency of orgasm has, like most other male sexual parameters, often been taken as defining sexual worth. The more orgasms the better, has been a general cry. It would not help the ego of most men to learn they can generally be beaten in this area by young boys.

In the Kinsey data, in a series of 182 observed cases, 81 of the preadolescent boys achieved orgasm only once. 17 achieved it twice, 42 achieved it three, four or five times in