174 Annals Entomological Society of America [Vol.1, 



It seems impossible to account for the condition produced upon 

 the basis of a latent character of this kind somewhere in the 

 ancestry of this genus. Moreover, all of the beetles in this experi- 

 ment had an equal chance to be accelerated by the conditions of 

 existence, so that this factor could not by any stretch of the 

 imagination be held to account for the development of this change. 

 As far as is known, the only changed factor in this experiment was 

 that used in the third generation upon the 7 males and 7 females 

 for three-fifths * of the reproduction periodf. From the germ 

 cells subjected to stimuli this race arose, but not at once, two 

 generations being necessary in which to disentangle the changed 

 character from the non-modified decemlineata." 



Therefore, in order to agree with Tower's results, the pro- 

 duction of eggs by the adults of the second generation of the 

 beetles reared by me in 1907, will have to be considered as due to 

 some abnormal stimulus present during maturization of the re- 

 productive elements, or as a racial characteristic; but it seems 

 to me that either supposition is improbable, because of the few 

 generations through which the beetles had been inbred. Tower's 

 evidence is poorly presented, without reservation or limitation in 

 places, it is contradictory and it is to be regretted that in a great 

 many places he has contented himself with giving general state- 

 ments without the accompan^^ing data as evidence; conditions 

 that produce controversy instead of establishing fact. When his 

 evidence is sifted, however, it is found that the following facts are 

 indicated as being true: 



1. That decemlineata, when bred in confinement in normal 



environments, in all cases goes through but two annual 

 cycles the second of which hibernates before reproduc- 

 tion. 



2. That decemlineata, when bred in confinement through 



more than three generations in abnormal controlled 

 environments, in the great majority of cases goes 

 through but two annual cycles, as in normal beetles. 

 3. That the species, when bred in confinement for more than 

 three generations in abnormal controlled environ- 

 ments, exceptionally may go through as many as five 

 annual cycles, this physiological variation being cor- 

 related with morphological variations of racial value, 

 produced suddenly. 



* One-half? (Cf. Statement of conditions, p. 288). 



t A foot-note follows here, which is omitted in the quotation. 



