Experime7its with Snails, Moths, and Beetles 147 



"2 J + iJ + I J + iV' which is the same as Galton's law, but so far as 

 I can interpret his data this is not strikingly apparent. Failing 

 to carry the results discussed above through subsequent genera- 

 tions leaves the matter in an unsatisfactory condition. In only 

 one experiment is the result of the next generation given, which 

 shows, if I interpret it correctly, that each of the four types 

 gives, when inbred (?), individuals amongst which most of 

 the same types reappear, but in very different proportions ; the 

 most striking result being that each type gives a much higher 

 percentage of its own kind. 



(9) In the course of separation of two characters which takes 

 place during a series of generations it happens at times that 

 when two similar individuals are paired, i.e. both having the same 

 character, the other contrasted character never appears again 

 in their descendants. It has not simply become latent, but has 

 gone entirely. 



It is obvious that this would happen, according to Mendel's 

 formula, whenever the individuals are pure dominants or pure 

 recessives. 



(10) Crossing individuals with different characters often gives 

 in the first generation a mixture, ''melange heterogene," of two 

 characters with marked predominance of one of them in the com- 

 bination, and in this case it is easy, by means of selection in suc- 

 cessive generations of the individuals having the most marked 

 character, to fix rapidly this character and even to exaggerate 

 its relation to the other. 



In cases of this sort it is not clear that Mendel's law holds at 

 all, and some other principle must be involved, especially if the 

 author means that the results are obtained by simply discarding 

 the individuals having the disappearing character and allowing 

 the rest to breed together. 



(11) Crossing two individuals with a different character often 

 gives in the first generation a separation of these characters in a 

 part of the offspring and in the other part a union constituting 

 a new character. Subsequent generations show a separation or 

 liquidation of these characters. 



