594 SIDNEY I. KORNHAUSER 
is evidence that the effect of the parasites is not accomplished 
through the destruction of the testes of the host (castration 
parasitaire), but that the parasites have a direct effect upon the 
developing tissues. 
The second significant individual was a nymph of the fourth 
instar. The author was dissecting a large number of nymphs 
Fig. 51 Cells from normal Thelia gonads and soma. a, spermatogonium, 21 
chromosomes including one x-chromosome, the largest of the group (x); b, so- 
matic cell from developing external genitalia, removed from fifth nymphal instar 
and stained with acetic-carmine, 21 chromosomes, one large x-chromosome; 
c and d, primary spermatocytes showing large x-chromosome; e, primary sper- 
matocyte, lateral view of first maturation spindle showing large unpaired x-chro- 
mosome; f, late anaphase of first spermatocyte division; g, spermatid which has 
received x-chromosome; h, o6gonium, 22 chromosomes including two x-chromo- 
somes (the largest pair); 7, somatic cell from developing external genitalia, acetic 
carmine, 22 chromosomes. X 1980. 
of this stage when he was surprised, upon opening the abdomen 
of a normal-appearing female, to find that a pair of testes, in- 
stead of ovaries, were present. ‘The testes were quickly re- 
moved, one preserved in Bouin’s fluid and the other prepared 
for immediate observation in Schneider’s aceto-carmine. The 
Bouin material sectioned (fig. 53) proved far more valuable than 
