48 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
the testis showed a considerable degree of development. Mott has 
recently reported active spermatogenesis in two men of 81 and 86 years 
of age. It does not seem as if age itself was sufficient to account for 
arrest of spermatogenesis and atrophic sclerosis of the testis. J. A. T. 
Fecundity of Fowls. — Raymond Pearl and W. F. Schoppe 
( Journ . Exper. Zool., 1921, 34, 101-18, 2 figs.). The functioning 
ovary when taken from the bird closely resembles a bunch of grapes. 
It is made up of a large number of oocytes held together by connective 
tissue, joined to a heavy stalk by which they are kept in place in the 
body. In counting the oocytes four groups were distinguished — (a) 
follicles from which the ova had been discharged, which ought to 
conform closely to the total number of eggs laid ; ( b ) oocytes over 
1 cm. in diameter ; ( c ) those over 1 mm. and under 1 cm. ; and ( d ) 
those under 1 mm. Thirty-six birds were studied, including various 
breeds of domestic fowls, water-fowl, and wild birds. In general, the 
mean number of visible oocytes on the ovary in different kinds of birds 
reflects the normal fecundity or laying activity of these kinds of birds. 
This relation does not hold with any exactness or regularity for differ- 
ences in fecundity between individual birds. In Barred Plymouth 
Rock fowls the number of visible oocytes increases with advancing age 
of the bird, within the age limits of 6 months and 87 months. It is 
probable that the oldest of the birds counted was not old enough to 
have reached the limit of ovarian rest. By removing a portion of the 
ovary and causing it to regenerate, the total number of oocytes develop- 
ing to visible size in the lifetime of the bird was caused to increase 
from 83 to 68 p.c. over the number which develop in the normal bird 
which has not been operated on. J. A. T. 
Development of Supra-renal Capsule in Hedgehog. — A. Celestino 
da Costa ( Gomptes Rendus Soc. Biol., 1920, 83, 878-9). At an early 
6 mm. stage the inter-renal primordium is distinct, and closely bound 
up with the genital primordium. The first traces of the sympathetic 
are seen at the stage of about 5 mm., and the penetration of sympathetic 
elements into the inter-renal primordium comes about very early — at the 
8 mm. stage. J. A. T. 
Transformation of Bidder’s Organ into an Ovary. — W. Harms 
{Zool. Anzeig., 1921, 53, 253-65, 8 figs.). From male toads showing 
a tendency to form ova in Bidder’s organ, testes were removed and the 
wounds closed up. The result was that Bidder’s organ turned in part 
into an ovary. It follows that a certain percentage of toads are herma- 
phrodites. It is well known that all have at least a residue of oviducts 
(uteri masculini). What the experiments showed was that the removal 
of the testes increases the potential femaleness. In some cases the ovary 
which developed from Bidder’s organ was large and the uteri masculini 
were much stronger than usual. But in other respects the animals 
remained males. J. A. T. 
Influence of Hypophysis on Pigmentation of Anuran Larvae. — 
W. W. Swingle {Journ. Exper. Zool., 1921, 34, 119-41,2 pis., 4 figs.). 
By transplantation experiments it has been shown that in frog larvae 
