210 
J. BRONTE GATENBY. 
aquarium from which it was known normal tadpoles could 
not escape. To my regret I found that just as the front 
limbs had broken through, the tadpole jumped out on to the 
floor, where it died before I discovered its plight. In figs. 3 
and 4 are drawn the gonads (T), kidneys (K), and rectum ( R ) 
of the parthenogenetic and normal tadpole respectively. 
When I sectioned the gonads of the former, I found that it 
was a well developed male, as the external appearance seemed 
to show, for the gonads were distinctly testiculiform. 
In section the germ cells are clearly marked into numerous 
incipient spermatic tubules ; though the section drawn in 
fig. 5 was across the least well-differentiated region, the 
spermatogonial nests are well marked. Undoubtedly the 
gonad had passed beyond the indifferent stage during which 
it is impossible to speak with certainty as to the sex. The 
part marked X in fig. 5 contains germ cells which have just 
begun to form spermatogonial groups, while that marked 
Y is apparently nothing more than a non-germinal core, the 
cells and their nuclei staining like the tissue forming the 
mesorchium (A.T.). 
I feel quite sure that this tadpole was a male. Mr. Goodrich, 
whom I have to thank for his usual kind interest and sugges- 
tions, lately drew my attention to an abridged account of a 
paper by J. Loeb read before an American philosophical 
society on the same question as that dealt with in this note. 
Loeb found that the sex of an American species of partheno- 
genetic frog a year old was male. I have not yet seen 
LoeVs paper, but his results agree with mine as to the sex. 
