420 SCIENTIFIC PROCEEDINGS (131)
8. Thus far no definite evidence has been obtained to show
that the carbohydrate tolerance of a diabetic patient is perma-
nently raised by temporary extract treament.
205 (2165)
The degeneration of the testis of rats on a milk diet.
By H. A. MATTILL and J. S. CARMAN.
[From the Physiological Laboratory of the University of
Rochester, Rochester, N. Y.]
The degeneration of the testis of rats on rations in which all
the protein and vitamines are supplied by milk' has also been
observed when such rations are supplemented by nucleoprotein
and by those proteins of first quality2 found in kidney and liver.
When 2 per cent. or 5 per cent. of these dried tissues or 2 per
cent dried thymus (Parke, Davis) or 2 per cent. yeast nucleic
acid was supplied in rations containing 50 per cent. dry whole
milk, 15 per cent., lard, 2 per cent., salts, and starch, evidences of
degeneration and atrophy appeared as early as 155 days of age.
Among 27 animals on such rations, the oldest animal still pos-
sessing normal gonads was 139 days of age. Of 25 animals
over 155 days of age only one had gonads whose weight was
normal and in this animals there were other evidences of degen-
eration. Without exception litter mates of these animals on
stock rat food had normal organs. Aside from the decreased
weight which was occasionally even less than one-half the normal
for the weight of the animal the degenerating glands have a
semitransparent glassy appearance; when ruptured they collapse
and there exudes a clear colorless liquid which coagulates like
lymph. Histologically these glands show a profound degenera-
tion of the germinal epithelium and an abundant proliferation
of the interstitial tissue together with numerous clear amorphous
areas. In the main these are the features which Allen3 de-
scribed as resulting from the absence of water-soluble B in the
diet. Since in our milk rations there can be little or no question
as to the adequacy of the vitamin B supply, especially when liver
or kidney is added, it would appear that the lack of some other
substance than vitamin B, and as yet unrecognized, may be
solely or jointly concerned in the disappearance of the repro-
ductive function.
1 Mattill, H. A., and Stone, N. C., Jour. Biol. Chem., 1923, Iv, 443.
2 MeCollum, E. V., Sinmmonds, N., and Parsons, H. T., J. Biol. Chem.,
1921, xlvii, 235.
3Allen, E., lnat. Rec., 1919, xvi, 93.