206 SMITHSONIAN MISCELLANEOUS COLLECTIONS [voL. 48 
turgid about the abdomen, the ovaries fully developed and the eggs 
ripe. The number of eggs is approximately proportioned to the 
size of the ovaries and consequently that of the mother-fish; in 
one of four or five pounds weight there may be 400,000 to 500,000 
or even more. In one weighing sixteen and a half pounds, whose 
ovaries weighed five and one half pounds, over 2,000,000 eggs were 
accounted for. The male has assumed external sexual character- 
istics in the form of protuberances, like warts, on the skin of the 
head and back, which disappear after the spawning season. His 
color also brightens. Some days before spawning, both sexes show 
increased vivacity, and “rise more often from the depths below to 
the surface.” Two or three or more of the males keep near a 
female and the latter swims near the surface followed by the males. 
“The female prefers spots which are overgrown with grasses and 
other kinds of aquatic plants.” The males follow close to the very 
water’s edge. “ They lose all their timidity and precaution, so that 
they may be taken quite easily. They lash the water in a lively way, 
twisting the posterior portion of the body energetically, and shoot- 
ing through the water near the surface with short tremulous move- 
ments of the fins. They do so in groups of two or three males to 
one female fish and forming an almost compact mass. This is 
the moment when the female drops the eggs, which immediately are 
impregnated by the milter. As this process is repeated several 
times, the female drops probably only from four hundred to five 
hundred eggs at a time, in order to gain resting time, so that it will 
require days and weeks ” before she gives up “ the last egg.” These 
eggs are adhesive, not detached, and adhere in lumps to the object 
upon which they have fallen. They average about a millimeter and 
a half in diameter and are of a yellowish color. 
As soon as the eggs have left the body they begin to swell and 
their mucus-like investment serves to fasten them to “ some aquatic 
plant, stone, or brush-wood. ‘Those eggs which have no such object 
to cling to are lost.” The eggs develop rapidly and development 
is hastened by increased warmth. Under ordinary conditions, “as 
early as the fifth or sixth day the first traces of dusky spots, the 
eyes, will be visible, and towards the twelfth, or at the latest the 
sixteenth, day the little embryo fish will break through its envelop.” 
After the yolk-bag has been absorbed, the young seek food for 
themselves and feed mostly on minute rotifers and copepod crusta- 
ceans, later on larval insects (the larvz of mosquitoes are especially 
acceptable), and in a few weeks are prepared to add to their diet. 
If the food be abundant, by the time cold weather causes cessation 
