26 DR. C. G. SELIGMANN AND MR. S. G. SHATTOCK ON THE 
February 14th. Full winter plumage. 
Testes soft, 15 mm. in length. Tubuli large and full of well-conditioned 
cells, but there are no spermatozoa or spermatids. Small groups of finely 
eranular interstitial cells are present. 
February 14th. Full winter plumage. 
Each gland is about 15 mm. long by 9 mm. in breadth, the tubuli are full of 
cells but contain no spermatozoa. 
March 7th. Full winter plumage. 
Weight of both testes together, 5800mg. Testes equal in size, bean-shaped, 
maximum diameter 25 mm. ‘Tubuli thickly lined with cells; a moderate 
number of spermatozoa in some tubuli, 7. e. spermatogenesis is in progress. 
March 16th. Full winter plumage. 
Weight of testes 9150 mg. Tubules of full size, occupied by dense masses 
of cells ; centrally there are numerous spermatozoa. 
(The testes of another bird, killed on the same day, together weighed 
10,170 mg.) 
March 22nd. Full winter plumage. 
Testes together weighed 32,500 mg. Hach was as large as a pigeon’s egg. 
Tubules of full size; typical picture of active spermatogenesis. 
April 20th. Full winter plumage. 
Testes large, about 50 mm. long; and so soft as to be almost diffluent on 
section: total weight, 30,140 mg. Spermatogenesis in active progress. 
May 7th. Pull winter plumage. 
Total weight of testes, 30,580 mg. Macroscopically and microscopically 
they resemble those of the bird killed on April 20th. 
May 30th. Full winter plumage. 
Testes size of a haricot bean; the tubuli are distended with cells, and 
contain large numbers of spermatozoa. The organ is, however, retrograding, 
as appears from the absence of spermatid sheaves, and the fact that the 
spermatozoa in the centre of the tubules are badly stained. 
May 80th. Full winter plumage. 
Hach testis, not larger than a small haricot bean, about 11 mm. long and 
7mm. broad. Tubuli, not of full size; there is a central area of vacuolated 
substance in which there are somewhat thinly scattered cells. No mitoses 
and no spermatogenesis ; the whole appearance is one of inactivity. 
June 6th. Full winter plumage. 
Testes narrow and firm, about 13 mm. long by 4mm. broad. Tubuli of 
somewhat small size, each with a peripheral layer of cells; the centre of the 
tubuli occupied by a vacuolated material in which cells are thinly scattered. 
There are no spermatozoa, but very fine deeply stained granules of chromatin 
oceur in moderate numbers in the centre of the material (chromatolysis). 
