NATURAL HISTORY OF AMIA CALVA LINNAEUS. 89 



are now ready to leave the nest. Although Fiilleborn says that the larvae remain 

 in the nest until about 13 millimetres long, Dean ('96, '96 a ) was unable to find them 

 in a nest which he visited shortly after the eggs had hatched and was inclined to 

 accept the suggestion of his companion, Kosmak, that they had been taken away 

 by the male attached to him by their sucking discs. Whitman and Eycleshymer 

 characterize this as "a bit of romance." Dean ('98) has since very properly aban- 

 doned the idea, for which there was at no time evidence, and says: "In 12-15 days a 

 length of 9-11 millimetres is reached. . . . About this time the larvae are ready to 

 leave the nest with the male fish." 



Several times I have heard fishermen relate that they have seen the males of 

 Amia swimming completely enveloped in larvae. At the same time they have taken 

 other males which were much emaciated and covered with small light-colored spots. 

 From these observations they believe that the young Amias attach themselves to 

 the male and are thus nourished. Thus they account for the spots and the emacia- 

 tion of the male. Highly improbable at any time, this story is rendered wholly 

 impossible by a knowledge of the fact that the young remain in the nest until the 

 adhesive organ has become functionless. The male is frequently seen enveloped 

 in the swarm of young. The spots observed by the fishermen may have been Arguli. 

 Thus, possibly, is this myth accounted for. 



8. History of the Larvae Outside the Nest. — I have followed the history of the 

 larvae outside the nest until they were 10 centimetres long. At this time they are like 

 the adult fish except in color, and it is probable that then or a little later the swarms 

 break up and the young Amias begin their independent life. But on the breaking 

 up of the swarms there are no observations. 



A. Leaving the nest. — How this takes place I have been able to observe 

 in detail twice. In nest 13 (1901) the larvae were on the nest in the morning, but 

 upon returning to the nest in the afternoon they "were found about a metre from the 

 nest toward the deep water, and the male was seen half a metre beyond them in 

 the same direction. The male discovered me and went off with great violence. 

 The larvse were swimming in a circle in a progressive swarm as though on the nest, 

 and when a stick was thrust among them and moved about they showed no signs 

 of fear, but moved toward the stick quite as often as from it. After the male had 

 left, the larvae continued swimming in a circle. The swarm broke into two and 

 each of these swam in small circles, continually returning to the point of departure, 

 their original location. The two groups sometimes joined and then the mass again 

 separated into two. The movements became rapidly more definite in the sense 

 that the individuals moved more constantly in a fixed direction with the mass. 



