HAY] HERMAPHRODITISM IN CRAYFISHES 223 
crayfish, Cheraps preissii,s in which the normal openings of the 
oviducts on the third pair of legs co-existed with male orifices on 
the fifth pair of legs. The specimens had been preserved in alcohol 
for several years and their internal organs were doubtless badly 
preserved. No ovary was detected and no oviduct leading to the 
openings on the third pair of legs. A similar arrangement of open- 
ings was noticed in males of Parastacus brasiliensis and P. pilimanus. 
In 1892 von Ihring’ reported that in Parastacus brasiliensis he 
had found that two sets of apertures, one on the third and the other 
on the fifth pair of legs, coexisted in every individual of the “ sev- 
eral dozen’ examined by him and that on dissection they all proved 
to be males. 
In 1898 Faxon® stated that not only Parastacus brasiliensis and 
P. pilimanus, but P. saffordi, P. varicosus, P. defossus and P. hasslert, 
as well, seemed invariably to possess two sets of genital orifices. No 
dissection of any of the specimens was described. 
In 1898 Loénnberg’* had an opportunity to examine a series of 
Parastacus hassieri and his observations form a most valuable con- 
tribution to the present discussion. He found that while the two 
pairs of genital orifices were present in every individual it was still 
possible by comparative measurements to separate his specimens 
into two lots, one of which from the broader abdomen, shorter 
antennae and weaker chelipeds he regarded as females, while the 
other, with an opposite set of characters, he took to be males. An 
examination of the internal anatomy proved the correctness of his 
theory. The males possessed only testes, the females only ovaries. 
The arrangement of sperm ducts and oviducts, however, was very 
remarkable. From each generative gland there were-two ducts 
passing downward, one to the fifth and the other to the third pair 
of legs. In the females the anterior of these ducts alone was com- 
plete and functional, the posterior one ended blindly and could be 
of no use. In the males the reverse was the case, the anterior 
duct ended blindly while the posterior one was functional as a sperm 
duct. A more critical examination of the external genital apertures 
was now made and it was found that in each case there was actually 
only one pair of openings, those on the third pair of legs in the 
males and on the fifth pair of legs in the females being only shams. 
1 Sitzungsberichte der Gesellschaft Naturforschender Freunde zu Berlin, 
18th Januar, p. 3, 1870. 
? Congress International de Zoologie 4 Moscou, Aug., 1892. 
* Proceedings of the U. S. National Museum, xx, p. 683, 1808. 
“Zoologischer Anzeiger, XX1, pp. 334-335 and 345-352, 1808. 
