Experiments with Snails, Moths, and Beetles 143 



Coutagne states that any one of the three kinds of larvae, white, 

 black, or zebra, may be associated with either of the two kinds 

 of cocoons, yellow or white. This gives six combinations. Any 

 of these six may be associated with either of the two kinds of 

 moths, white or black, giving a total of twelve possible combi- 

 nations. The following results were obtained : — 



(i) Crossing individuals with two different characters often 

 gives offspring in the first generation that are intermediate in 

 character. Thus the race Chang-hai has a white cocoon that is 

 small and spherical, while the race Jaune Var has a rose-yellow 

 cocoon that is large and eUipsoidal with a constriction.' The 

 cocoons of the hybrid have a pale yellow tint, about intermediate 

 in color,^ the form also is intermediate — elHpsoidal, but less 

 elongated, and the constriction absent or scarcely marked. 



(2) Crossing individuals of different races may give in the first 

 generation a fusion of two characters, but subsequent generations 

 descended from the first show a mixture of the two characters 

 in question. 



The statement is also illustrated by reference to cocoon-char- 

 acters, but the line of separation of the colors does not appear 

 very sharp. 



(3) When the crossing has given a fusion in the first generation, 

 and in the second generation a mixture ("melange heterogene")? 

 it is possible to produce a homogenous race, by means of selec- 

 tion, that shows the characters that fused. In each successive 

 generation the individuals presenting the united characters, i.e. 

 those "fondus,'* must be selected. This statement Coutagne 

 puts in the form of a question, because he has not, he says, 

 indisputable facts in support of it. 



(4) Crossing individuals with different characters often gives 

 a separation in equal parts of the two characters. For example, 

 an individual of a race having white worms, white cocoons, and 

 white moths was crossed with an individual of a race having 



' Two to three per cent, however, were pure white, small, and spherical (type 

 Chang-hai) ; and 4 to 5 per cent were yellow, nearly of the yellow type but less 

 yellow. These Coutagne suggests were due to accidental mixing. 



