Experiments with Snails, Moths, and Beetles 149 







Coutagne calls attention to the reappearance of the white char- 

 acter that is atavistic on his interpretation. It will be noticed 

 in each group the numbers are nearly exactly halves, thus 70 

 and 189, 27 and 61, n and 23, 39 and 77. 



Although it is not apparent that an application of the Mende- 

 lian law is competent to explain all the results of these experi- 

 ments, it is probable that some such rule lies behind several of the 

 observed cases. Other cases clearly show blended inheritance, 

 and still others show in some characters one kind and in others 

 other kinds of inheritance. It is difficult in many cases to under- 

 stand just what really occurs, but the results show plainly how 

 complicated the problem of inheritance in a single group of 

 forms may be. 



In a note published later, Coutagne compares his results with 

 the Mendelian formula and points out that certain classes of his 

 results conform to this law. It seems to me not improbable that 

 if the latent qualities of some of the races be taken into consid- 

 eration, the conformity may be greater than Coutagne admits. 

 On the other hand, it appears probable that some characters do 

 not dissociate according to the Mendelian expectation. 



A shprt paper by Toyama on Mendel's law as applied to silk- 

 worm crosses has very recently appeared, in which it is shown 

 that many of the same characters studied by Coutagne give the 

 Mendelian expectation. Unfortunately no reference is made to 

 Coutagne, although a comparison would have been valuable. 



When moths of the Siamese breed, having either yellow or 



