the other testis. 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. This is rather a surprising conclusion in view of the
fact that testicular grafts show active spermatogenesis. It is difficult
to understand why nerve connection should be necessary for the
interstitial cells and not for the spermatic, and, moreover, if the
interstitial cells are really the source of the hormone on which the
somatic characters depend, they must be acting in the grafts in which the
nerve connections have been all severed.

The facts concerning cryptorchidism, that is to say, failure of the
descent of the testes in Mammals, seem to show that the hormone of the
testis is not derived from semen or spermatogenesis, for in the testes
which have remained in the abdomen there is no spermatogenesis, while the
interstitial cells are present, and the animals in some cases exhibit
normal or even excessive sexual instinct, and all the male characteristics
are well marked. It may be remarked, however, in criticism of this
conclusion that the descent of the testes being itself a somatic sexual
character of the male, its failure when the interstitial cells are normal
and the spermatic cells defective, would rather tend to prove that the
defect of the latter is itself the cause of cryptorchidism.

Many investigators have found that the Roentgen rays destroy the spermatic
cells of the testis in Mammals, leaving the cells of Sertoli, the
interstitial tissue, nerves, and vessels uninjured. Tandler and Gross
[Footnote: _Wiener klinische Wochenschrift_, 1907.] found that the antlers
of roebuck were not affected after the testes had been submitted to the
action of the rays, showing that the interstitial cells were sufficient to