THE GERMAN CARP IN THE UNITED STATES. 579 
our Southern States the development is more rapid; in a pond in Geor- 
gia, when the temperature of the water was 69°, the eggs are reported 
to have hatched in five to six days, while the following year, with the 
water still warmer, the whole time consumed for development was but 
forty-eight to seventy-two hours (statement of H. H. Carey, M. D., 
Smiley, 1886, p. 687). The young fish also grow very rapidly and in 
the latitude of Lake Erie reach a length of 4 to 6 inches the first fall. 
DISEASES, PARASITES, AND ENEMIES OF THE CARP. 
The most remarkable fact in this connection seems to be that, 
although deformed and misshapen individuals are by no means rare, 
carp in the Great Lakes region appear to be very strong and hardy 
and almost free from diseases, whether such as are due to parasites 
or to other causes. This fact impressed me especially while I was 
working with them in the fish houses on Lake Erie, where I had a 
good opportunity to compare them with large numbers of. other lake 
fishes. One finds intestinal parasites in almost any of the other species 
in great abundance, but in large numbers of carp examined I have 
found parasites in the alimentary tract in only one case. This was a 
rather large fish, which had some 16 round worms, nearly chrome 
yellow in color and 2 to 2.5 em. (four-fifths inch to 1 inch) long, hang- 
ing to the walls of the intestine. Their spiny probosces were buried 
in the intestinal wall in true acanthocephalous fashion, and it required 
a considerable pull to detach them. ‘These specimens were referred 
to Mr. H. W. Graybill, who studied the parasites of many of the 
Lake Erie fishes in 1901. Mr. Graybill reports that these are a form 
closely related to Hchinorhynchus proteus, though he thinks they are 
possibly specifically distinct from that type. He further states that 
in 1901 he found in a carp a single dwarf specimen of the same worm. 
Excrescences of the integument, probably caused by sporozoa, are 
not infrequent on the wall-eyed pike (S¢tizostedion), and were occa- 
sionally found on other species, but I did not observe them at all on 
carp. 
In one case I found a leech attached to the base of one of the pec- 
toral fins of a carp, but unfortunately the specimen was lost before it 
could be preserved, so that I have been unable to have it identified. 
The only Lake Erie fishes on which I observed leeches at all commonly 
were the lake lawyer-(Lota macu/osa) and some of the cat-fishes (espe- 
elally Zctalurus). 
There can be no doubt that the lampreys must also be considered 
among the external parasites of the carp, though J have never myself 
seen one attached toacarp. The fishermen told me that ‘‘lamper eels” 
were ‘‘common” up the Portage River, and I often found them among 
the fish brought to the wholesale house from both the river and the 
