NEW SPECIES 



99 



out and fell to the ground like bristling small porcupines. 

 Moreover, their children and their children's children showed 

 fright in the same way. Dr. Tower saw that his damp-heat en- 

 vironment had changed the leg habits of multitaenita beetles. 

 It had made melanothorax beetles out of them, and they con- 

 tinued to be melanothorax beetles for succeeding generations. 

 A wonder of this sort throws a flood of light on the laws of 

 inheritance and on one of the methods of evolution. 



Mutations Compared 



Lt-ptinoiarsa mullitaenita (2) and two of its offspring that were mutations — rubi- 



cunda (1) and melanothorax (3). In their coloring 2 shows black stripes and marks 



on a yellow background ; 1 has similar stripes and head markings on a red background ; 



3 is red with black stripes and a black neck. (After W. L. Tower) 



The most notable part of Dr. Tower's work was the proof 

 that, by giving beetles an unusual environment during the 

 time that the eggs were maturing, before they are laid, germ 

 cells may be influenced and a new species secured. 



Now it matters little whether beetles feign death in one way 

 or in another. But suppose there were some sort of environ- 

 ment which could change cells in such away that the individuals 

 of the next generation would be hopelessly damaged after birth. 

 This subject will be studied later. Just now we turn our atten- 

 tion to the very beginnings of life for the next generation. 



