1 84 NATURAL SCIENCE. ^^; 



Nor can it be distinguished from idioplasm (pp. i8o, 200). Nor, we 

 may add, can either one or the other be practically differentiated, but 

 only by the imagination, from what is known as protoplasm, which, 

 however complicated its structure may prove to be, appears to be 

 perfectly capable of acquiring new characters and fixing them by 

 heredity. 



George Henslow. 



