PARENTAL CARE AMONG FRESH-WATER FISHES. 433 



find " twentv-fnH' freshly laid "' ones. Eggs *' may be over tlie whole 

 inner surface of the nest, on the bottom only, or on one side onl3\ 

 If fibrous roots are present, they are invarial)ly on these. '"■ 



The stock of eggs being provided, the male bowfin redoubles his 

 guardianship and " lies for the most part motionless, or with only 

 slight movements of his fins, but at intervals he moves over the nest 

 and thus by the movements of his fins keeps the eggs free from sedi- 

 ment, which would otherwise smother them." All the time he is on 

 the outlook for intruders, and especially against otlier males. One 

 Eeighard saw ruslied at another male and " struck him with his head 

 in the middle of tlie side and hurled him two feet from the nest." 

 Generally there is no contest, for the rights of the nest maker ap- 

 pear to be respected, l)ut occasionally too great aggressiveness on the 

 part of the occupant or audacity of an intruder results in a regular 

 battle. Whitman and Eycleshymer tell of one : Two males that 

 claimed a female were unwilling to yield, one to the other, and " a 

 fierce battle for supremacy ensued " between them. " They ap- 

 proached from opposite sides of the nest and locked jaws in a most 

 ferocious manner. Their struggles were so violent that a cloud of 

 muddy water soon arose and obscured them from view." Eventually 

 one of the males was left about the nest, and his attentions were 

 accepted by the female, who, "' during the battle, had remained con- 

 cealed at the side of the nest." 



Vigilant though the watching may be, it is not entireW continuous 

 during the period of incubation ; Reighard found " that at many 

 visits " males were not found over their nests " in spite of careful 

 search through all the surroundings." The absences were most nu- 

 merous in the morning and least so in the afternoon. But day after 

 day the nest is guarded most of the time. Nine days elapse before the 

 eggs are hatched and seven to nine more before the larvae are prepared 

 to leave the nest. The newly liatched larva? are not quite a third 

 of an inch (7 millimeters) long; those ready to take to free life are 

 nearly half an inch (11 to 12 millimeters) long. By this time black 

 pigment has developed and the whole body except the belly is " very 

 dark greenish black or greenish brown." The swarm reminds one 

 both of a swarm of tadpoles and a swarm of bees. First the larva^ 

 are stationary and tlien they commence to move. " They swim to- 

 gether in a swarm which moves in a genei'ally circular direction al)out 

 the edge of the nest or just outside it. The larva', though not pro- 

 gressing continuously as individuals, form a swarm which neverthe- 

 less jn'ogresses, one way or another, Avith many internal irregulari- 

 ties." The course of a school from which its guardian was frightened 

 away has been well epitomized and illustrated by Reighard. 



" This swarm was among hummocks (dotted areas) and bunches 

 of grass (lined areas), and Avhen the observation began w^as at A. 



