448 
GEOFFREY SMITH AND EDGAR SCHUSTER. . 
No. 9. — Male frog, with one testis from male C, implanted 
on September 30th, 1910. Killed September 7th, 1911. 
Time in body, 11 J months. This is a parallel experiment to 
No. 6, and again shows exactly the same result. The testis 
(fig. 13), which was attached to the bladder, consists, as in 
experiment No. 6, of a small mass of fibrous tissue enclosing 
a small amount of granular chromatic material, derived from 
broken-down spermatozoa that have not been completely 
absorbed (cf. fig. 8). 
Auto-Transplantation of Testes in Male. 
Two successful experiments were made, in which both testes 
were severed from their connections with the body and left 
loose in the peritoneal cavity of the same individual. Thus 
as regards vascular supply and connection with the body, 
the severed testes were in the same position as in the allo- 
transplantation experiments, the only difference being that 
they were implanted in the body to which they naturally 
belonged, instead of being transferred to another body. 
Nevertheless, as the experiments show, their fate is a very 
different one. 
No. 10. — Male frog, in which both testes were severed from 
all connections and left in the peritoneal cavity October 10th, 
1909. Killed March 25th, 1910. Time in body 5J months. 
Both testes were found reattached to peritoneum of body- 
wall, one highly vascularised (fig. 14), the other very 
slightly (fig. 15). The highly vascularised testis shows an 
enormous infiltration of blood, the blood sinuses (hi. sjp.) sur- 
rounding the highly degenerate masses of spermatozoa (fig. 
16). There is no phagocytosis to be observed. Round the 
edge of the testis are small tubules (figs. 16 and 17) lined 
with living spermatogonia of different sizes, which suggest a 
recent proliferation of the germiual cells. There is very 
little fibrous tissue. In the second testis the one side of the 
whole of the centre is composed of fibrous tissue (figs. 15 and 
18), a part of which, at any rate, appears to be of a secondarily 
