64 THE AMERICAN NATURALIST [Vol. XLV 



He further remarks on page 328 : 



The statement on page 335, that characters which Mendelize 

 are in the main unimportant attributes of the organism and 

 only rarely are of importance in the struggle for existence, 

 is a little bit strong. xYpparently it would have been better to 

 state that those characters which have been shown to Mendelize 

 are of this nature. Unfortunately, most of the work of the 

 Mendelians has been done with these superficial, easily observed 

 characters. I see no reason why any character whatever might 

 not, from the failure of some chromosome to perform a usual 

 function, give a variation which would behave in Mendelian 

 fashion if the resulting type were capable of propagating and 

 crossing with the parent type. 



Tower's paper will undoubtedly have an important influence 

 on biological thought, as it deserves to have. 



W. J. Spili.man. 



