HABITS OF THE BLACK ORAPPIE. rl 
small crappies captured were empty, which indicates that the young, 
as well as adults, may cease to eat at times during the winter. The 
most important foods for the young crappies were Cyclops, clado- 
cerans, and small insect larve. ‘The young fishes eat the same gen- 
eral classes of foods as the adults, but depend more upon Cyclops and 
cladocerans than upon insect larve. 
During the winter of 1917 two young crappies were kept in the 
laboratory in order to make observations on feeding, amount of 
food consumed, and rate of digestion, for comparison with young 
perch kept under the same conditions and simultaneously fed the 
same foods. The crappies each measured 58.5 millimeters in length 
(without tail) and had a volume of 4 cubic centimeters. The length 
of each of the perch was 62 millimeters and the volume 38 cubic centi- 
meters. At the temperatures indicated the rate of digestion in the 
crapples, as judged by the first appearance of the foods in the feces, 
was as follows: Chironomid larve, 15.2° C., 24 hours; Corethra lar- 
vee, 18° C., 24 hours; earthworms, 16.5° C., 21.3 hours. Amphipods, 
minnows, and snails were not eaten. Under the same conditions the 
record of the perch was: Chironomid larve, 18° C., 22 hours; Co- 
rethra larve, 18° C., 23 hours; earthworms, 17.5° C., 18.3 hours; min- 
nows, 16.8° C., 18.7 hours. In proportion to their own volume the 
crappies ate as follows: Chironomid larve, 12 per cent in 6 hours: 
earthworms, 5 per cent in 1 hour. The perch ate chironomid larve 
amounting to 23 per cent of their own volume in 6 hours, and 20 
per cent minnows in 2} hours. From these observations it is con- 
cluded that the rate of digestion is about the same in the two species, 
or perhaps slightly more rapid in the perch. The crappies were less 
ageressive in their feeding reactions, and ate less at a time than the 
perch. The two perch ate 31 chironomid larve in 6.3 hours; the 
crappies ate 20 of the same size in 6.3 hours. A comparison of the 
food of the adult perch and crappie is made in another paper (Pearse 
and Achtenberg, forthcoming report). The crappie feeds more on 
pelagic crustaceans and less on the small animals associated with the 
bottom than the perch. 
III. REPRODUCTION. 
Richardson (1913) describes a nest of the black crappie, found May 
2, 1911, in a pond near Havana, IIl., after the temperature of the 
water had reached about 19° C., as follows: 
It was hollowed out under the leaves of a water parsnip and surrounded 
by smartweed and bog rush (Juwnctus). Some of the eggs were adhering 
to fine roots in the bottom of the nest, but most of them were on the 
leaves of the water parsnip at a level of 2 to 4 inches above the bottom of the 
nest. The nest was guarded by a male 6 inches long, who was so gentle that 
we could reach outa hand to within 3 feet of him before he moved away. 
Eggs taken to the laboratory hatched May 8 and 4. Both eggs and newly 
hatched fry are even smaller than those of the bluegill sunfish; and the great 
transparency of the new fry, along with their small size, make it difficult to 
see them in an aquarium. 
In the spring of 1916 the ice left Lake Wingra March 26. On 
April 25 the temperature of the lake was 10.6° C.; May 138, 16°; 
May 27, 26°; June 11, 20.5°; July 20, 30°. On May 20 about a dozen 
male crappies were observed in nests along the base of a clay bank 
in one of the lagoons in Vilas Park, at the northeast corner of the 
