4 An Examination of Weismannism. 



a large extent dependent on others, is likewise to 

 a certain extent independent or autonomous, and has 

 the power of multiplying by self-division. Therefore, 

 as it is certain that the sexual elements (and also buds 

 of all descriptions) include formative material of some 

 kind, the first assumption — or that which supposes such 

 formative matter to be particulate — is certainly not 

 a gratuitous assumption. 



Again, the second assumption — viz., that this par- 

 ticulate and formative material is dispersed throughout 

 all the tissues of the organism — is sustained by the fact 

 that, both in certain plants and in certain invertebrated 

 animals, a severed portion of the organism will develop 

 into an entire organism similar to that from which it 

 was derived, as, for example, is the case with a leaf of 

 Begonia, and with portions cut from certain inver- 

 tebrated animals, such as sea-anemones, jelly-fish, &c. 

 This well-known fact in itself seems enough to prove 

 that the formative material in question must certainly 

 admit, at all events in many cases, of being distributed 

 throughout all the tissues of living organisms. 



The third assumption — or that which supposes 

 the formative material to be especially aggregated in 

 the sexual elements — is not so much an assumption 

 as a statement of obvious fact ; while the fourth, fifth, 

 sixth, and seventh assumptions all follow deductively 

 from their predecessors. In other words, if the first 

 and second assumptions be granted, and if the theory 

 is to comprise all the facts of heredity, then the 

 remaining five assumptions are bound to follow. 



To the probable objection that the supposed gem- 

 mules must be of a size impossibly minute — seeing 

 that thousands of millions of them would have to 



