200 NATURAL SCIENCE. Sept.. 1895. 



all females, we shall, I think, encounter difficulties similar to, and as 

 great as, those which beset the question, " Are there any characters 

 common to all animals which separate them from all plants?" Every 

 species has its peculiar dimorphism, and only in nearly allied species 

 are these dimorphisms similar. The organs of copulation present in 

 the mammal are absent in a large number of non-mammalian types ; 

 in one form the hair, in another form the horns, in another form 

 the wattles, in another form a different pigment of the skin or 

 plumage, serves some useful purpose and distinguishes the sexes. 

 The attempt to establish the male sex as preponderatingly katabolic, 

 and the female as preponderatingly anabolic, falls to the ground as 

 soon as we carefully examine the case. If we take size — an unsatis- 

 factory test at most — as an indication of a preponderance of 

 anabolism., we find examples of both females and males who are 

 larger than their partners in life. The female dipteron, ant, spider, or 

 frog may be larger than the male, but the male bird generally, and 

 the male mammal invariably, is bigger than the female. As to an 

 active katabolic constitution, it is true that some males are more 

 active than their partners, but it is doubtful whether this is the case, 

 say, with the carnivora and with most birds ; there is no difference in 

 the starfish, and the advantage is with the female in those cases 

 where the male is parasitic. 



It is highly probable that plants and animals developed out of 

 very primitive forms, adapting themselves in a thousand ways to their 

 surrounding conditions, so that we can find among some plants and 

 some animals almost every quality possessed by living beings. It is 

 impossible to say that a certain quality A is present in all plants and 

 distinguishes them from all animals, and the attempt to find such 

 qualities, at one time considered so important a matter by biologists, 

 is being given up. Now, in just the same manner, we are bound to 

 believe that the individuals carrying the male and female cells 

 became modified in a thousand ways ; so much so that there is no 

 quality which serves to distinguish all male from all female individuals, 

 except, indeed, that they carry respectively male and female repro- 

 ductive cells. 



J. B. Haycraft. 



