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I was surprised to find in the collection at New Haven a fine specimen of the great fossil salamander of Oeningen, the "Homo diluvii testis" of Scheuchzer. From New Haven I went to New York by steamboat.
At the same time the male instincts and the other generative organs were unchanged. In a few cases, however, Ancel and Bouin observed atrophy of the interstitial cells as well as the spermatic cells. They believe this is due to the nerves supplying the testis being included in the ligature.
Many of the patients converse with the doctor while the operation is proceeding. The pain is negligible. The doctor proceeds according to the condition, age, etc., of his patient. He may ligate, that is to say, tie off, the tubes that connect with one testis, or the other, or both; he may not ligate at all. It will depend upon the result sought, the condition present, and the age of the patient.
The so-called descent of the testicles occurs exclusively in Mammals, in which with a few important exceptions it is universal. This is a very remarkable case of the change of position of an organ in the course of development. The original position of the testis on either side is quite similar to that of the same organ in birds or reptiles.
My own experiments in castrating cocks were as follows: On August 20, 1910, I operated on a White Leghorn cock about five months old. One testis was removed, with a small part of the end broken off, but the other, after it was detached, was lost among the intestines. On the same day I operated on another about thirteen weeks old, a speckled mongrel.
When pieces of testis were introduced into the dorsal lymph-sac of a castrated frog the thumb-pads and muscles developed as in a normal frog. Mic. Smith and Schuster begin by describing the normal cycle of changes in the testes on the one hand and the thumb-pad on the other. After the discharge of the spermatozoa in March or April the testes are at their smallest size.
The experiments were performed on Herdwick sheep and domestic fowls. They state that on examination the testes were found to be normally developed, and spermatogenesis was in progress. The experiments of Ancel and Bouin were carried out on rabbits seven to eight weeks old, and consisted in removing one testis, and ligaturing the vas deferens of the other.
There the abdominal wall on either side of the middle line becomes thin and distended to form a pouch, the scrotal sac, into which the testis passes, still remaining attached to the peritoneum which lines the pouch, while the distal end of the vas deferens retains its original connexion with the urethra.
It might be thought that in this case, although the hormone theory of heredity might be applied, there was no reason to suppose that a hormone derived from the testis in the individual development was necessary in order that the hereditary change should take place. If the individual was male and therefore had a testis, this organ would by heredity go through the process of dislocation.
As I happen to have a lithograph of the original specimen of the Homo deluvii testis of Scheuchzer, I will forward it to Professor Silliman with this letter. I expect you will find it the counterpart of the specimen in your museum; or very nearly in the same state of preservation.
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