EXPERIMENTS UPON THE LEPIDOPTERA. 221 



for this assumption was found in the recorded instances of 

 hermaphrodite moths where dimorphic sexual coloration oc- 

 curred. Such a specimen, one of Saturnia io, the writer has 

 seen at the American Museum of Natural History in New 

 York. In this specimen the wings of one side are colored 

 like those of a male, those of the other like those of a female. 

 Oddly enough, the antennae and legs are correspondingly dif- 

 ferent in form. The interesting feature, however, is this: that 

 the orange color of the male is clouded by a faint purplish 

 overtone, and the dull female colors are considerably lightened 

 by a yellowish tinge. In other words, the male colors are 

 affected by the female half, and vice versa. 



The problem of heredity involved is the question whether 

 the color and the gonad of a certain sex are both the effects of 

 a common set of causes, or whether the color is more directly 

 dependent upon the presence of a gonad of a certain sex. As 

 the color is produced by a chemical decomposition of the hae- 

 molymph, and as the haemolymph can hardly escape being 

 reciprocally affected chemically by the sexual organ that it 

 bathes, the second of the above possibilities would appear to be 

 indicated. The relation of these experiments to the subject of 

 internal secretion, recently put forward by Mathews, is quite 

 obvious. However, the data at present available are not suffi- 

 cient to warrant any hard and fast conclusion. 



The pupae used in my experiments were those of Philosamia 

 cynthia, Samia cecropia, Callosamia promethea, and Teled 

 polyp/iemus, all belonging to the family Saturniidae. At first, 

 during the months of February and March, all experiments 

 were performed upon cynthia, in order to ascertain if any 

 fusion at all were obtainable. As the operated pupae in some 

 cases continued to live, success was reasonably assured and the 

 other species were then obtained, although in small numbers, 

 in order to determine the other facts; viz., the possibility of 

 reciprocal color effect upon each other of different species and 

 of different sexes. These latter pupae, however, had been 

 brought indoors at various times during the winter and spring, 

 and were consequently at different stages of advancement a 

 fact which materially lessened the chances of successful fusions. 



