1909] The Ottawa Naturalist. 91 



smooth. The seeds of this were preserved and again sown with 

 the result that ah the plants coming from them showed the same 

 pecuharity. Each successive progeny from this seed showed the 

 same characteristics as long as the experiment was conducted. 

 When the smooth variation was crossed with the original forms 

 true hybrids were produced which, in the second generation, 

 reverted to the original type. 



We probably have many so-called rare species at the present 

 time which have been created in a like manner. Mivart believes 

 that all species arise in this way. He claimed to be able to 

 recognize an internal law presiding over the action of every part 

 of every indi\-idual and of every organism as a unit. His theory 

 is a sort of a compromise between evolution and special creation. 

 While it has many things in its favor and while many of the 

 objections which apply to the theory of natural selection do not 

 apply in this case, yet it will not account for all of the facts of 

 nattire, and can only be considered to constitute one of the pos- 

 sible factors in organic evolution. 



weismannian theory, or neo-darwinism. 



In 1883, Weismann, a German Naturalist, undertook to 

 show how' acquired characters cannot be transmitted and how 

 permanent variations can originate. He outlined the develop- 

 ment of the individual from the single cell, the fertilized egg, 

 showing how the cell divides and how, while those cells which go 

 to build up the different parts of the body become differentiated, 

 other cells, the reproductive or germ cells, remain constant. 

 Continuing he attempted to show that the property of being able 

 to transmit definite characters to the oft'spring is peculiar only 

 to the germ cell, hence permanent variations must emanate 

 from this cell. Since environment can effect the body or soma 

 cells and not the germ cell, it is clear, according to Weismann, 

 that acquired characters cannot be permanently transmitted. 

 At the same time it is reasonable to believe that the temporary 

 "fattening" or "starving" of the germ cell due to the favorable 

 or unfavorable environment of the individual which bears it 

 would be noticeable for one or tv/o generations as indeed seems 

 to be the case. 



Galton in his book on " Nattiral Inheritance" disparages the 

 idea that progression can take place only by the accumulation of 

 minute variations, and characterizes such an inference as falla- 

 cious. 



Bateson, in his "Material for the Study of Variation" refers 

 to the two possible wavs in wdiich variations may arise and points 

 out the principle objections to the claims made for fluctuating 

 variations while at the same time he collates many facts respect- 

 ing the importance of discontinuous variations. 



{To be continued) 



