Survival of spermatozoa in the reproductive tract of the bitch was studied by examination of the female genitalia at measured intervals after copulation. Motile spermatozoa were found in the lumen of the uterus in undiminished concentrations for 4 to 6 days after copulation; numbers progressively declined but motile spermatozoa were observed as late as 268 hr after copulation. Clusters of spermatozoa were observed in a high percentage of the uterine glands. The disappearance of spermatozoa was associated with the onset of metoestrus, not with time in the uterus. Bitches bred late in oestrus and examined in metroestrus had few spermatozoa compared with bitches examined in oestrus at a comparable time after copulation. Large numbers of spermatozoa were never found in the oviducts or ovarian bursae; they were consistently found here between 20 and 40 hr after copulation, a single observation showed spermatozoa in the oviducts at 168 hours. Tubal ova were recovered from eight bitches in metoestrus, in five cleavage had begun; tubal ova were recovered from four bitches in oestrus, none had undergone cleavage. Examination of the ovaries indicated that ovulation most commonly occurred within 48 hr after the onset of oestrus.

No abstract

Pituitaries of slaughtered sows were assayed for prolactin with the intradermal pigeon crop gland technique. Sows were classified into three groups\p=m-\follicular,early postovulatory and luteal\p=m-\after gross inspection of the ovaries. Pituitary prolactin was lowest in the postovulatory group (57\ m=. \ 6\ m=+-\ 2\ m=. \ 4i.u.) and highest in the luteal group (87\m=.\0 \ m=+-\ 12\m=.\9 i.u.). This study indicated that the pituitary prolactin content in the sow was comparable with that reported for dairy cows and refutes previous reports of small quantities present in the swine pituitary.

The oxygen uptake of bovine endometrium was less when perfused with seminal plasma than when perfused with Krebs-Ringer phosphate buffer solution. Dialysing the seminal plasma against Krebs\x=req-\ Ringer phosphate buffer solution did not alter the depressant action of the seminal plasma. The depressant substance was shown to be partially heat labile.Variable mineral concentrations were not responsible for the respiratory depression of the endometrium. It was found, however, that calcium is contributed to the seminal plasma in various amounts and that this contribution is made in conjunction with or associated with the non\x=req-\ dialysable depressant substance. Calcium does not appear to be tightly bound to the non-dialysable material and its removal does not alter the depressant action.It was shown that the degree of respiratory depression is related to the dry weight of non-dialysable seminal plasma.

This lecture commemorates Frederick Grant Banting, his life and his work, bringing once again into the focus of our immediate attention the achievement for which the world will always keep his name in honor. There is no need, of course, for me to remind you, the members of a Diabetes Association, of this special reason for keeping him in grateful memory. There is no possibility that you will ever forget the enterprise which, some 33 years ago now, he led with such vigor and insistence, and with a youthful enthusiasm unblunted by experience. And there are others, of course, whose work we think of with Banting's, and who are still alive, to know that we remember. There is Charles Best, Banting's younger comrade and his full partner in the work which gave the first clear proof that insulin had a real existence, and that its extraction on a practical scale ought not to be beyond the reach of conservative methods, when these could be developed in detail. It is good to know that Professor Best, still at the height of his powers, is leading an eager team of his colleagues and pupils in Toronto, and fulfilling the brilliant promise of that early triumph, when he shared with Banting in the great discovery which we commemorate. There is J. B. Collip, too, whose work did much to speed the developments required to bring insulin within the range of practical and regular production, from ordinary, slaughterhouse pancreas. Professor Collip, we rejoice to know, is also still fully active, leading his own research team, and carrying an administrative burden for the new generation, as Dean of the Medical Faculty in London, Ontario. And there was J. J. R. Macleod, head of the Physiological Department in Toronto when the early work on insulin was done there, who was prompt to organize men of his own training into a team to hasten its practical development, as well as to begin the study of its significance for normal and fundamental physiology. Professor Macleod, however, afflicted by ill-health, returned later to his native Scotland, where he died some years ago.