114 MARINE BIOLOGICAL LABORATORY. 



young are not affected. Mutilation, among savages, of 

 the nose, face, and ears has been carried on for genera- 

 tions, yet no traveller has reported that either the 

 mutilations or the scars are inherited. All these facts 

 should be borne in mind when it is claimed, as it still 

 is by many, that acquired characters may be and are 

 inherited. Weismann admits that the long-continued 

 effect of climate and food may to some extent act on 

 the germ-cell ; but the idea that species can have 

 originated through the inheritance of the peculiarities 

 acquired by their ancestors, is contrary to his theory. 



Now the young of the Metazoa inherit the main 

 characters of their parents, for the same reason that 

 the young Protozoon resembles the form from which 

 it springs, — they are made of the same stuff. Germ- 

 cells and body-cells arise from the same germ-cell. 

 During the development of the individual the immortal 

 portion of the germ-cell is set aside to form the next 

 generation. The characters which the body of the 

 individual may acquire during life must be very funda- 

 mental to affect these germs. A young Metazoon is 

 a part of its parent, because the stuff of which it is 

 made is a part of the germ-cell from which its parent 

 was made. It may also resemble a grandparent or a 

 great-grandparent, for its parent sprang from a part 

 of the same germ cell which built its grandparent. Its 

 great -grandparent was in turn a part of its great-great- 

 grandparent. Thus every individual is made up of the 

 same material as its ancestors, in degrees varying with 

 the different generations. In ten generations an indi- 

 vidual may have 1024 ancestors, of all of whom the in- 

 dividual itself is a part. If the theory of the continuity 



