132 ORGANIC EVOLUTION — THE FACTOBS 



produced by tte force in the parent ; but that it is 

 asserted that this coincidence, this mere coincidence, 

 must, from the nature of the case, be extremely rare — 

 so very rare that, as factors in evolution, such apparent, 

 but only apparent, transmissions of acquired traits may 

 practically be ignored. 



Epilepsy must depend on structural changes in nerve- 

 matter, either gross changes, or molecular changes 

 induced by alteration in the nutritive fluids, or by altera- 

 tions in the nervous impulses received, or by spreading 

 degenerative or inflammatory changes. If upon ex- 

 tended inquiry it were found that the structural 

 changes in the nerve-matter of the ofifspring did not 

 correspond to the structural changes in the nerve- 

 matter of the parent, then this would be no true 

 instance of the transmission of an acquired variation; 

 for the epilepsy, though present in both parent and 

 ofispring, would be due to different causes. But if the 

 structural changes in the offspring were found to be 

 similar to those in the parent, it would have to be 

 admitted that in this case an acquired variation had 

 seemingly been transmitted; and the question would 

 then arise as to the nature of the transmission, as to 

 whether it was a true transmission of an acquired 

 variation in the sense meant by those who contend that 

 acquired variations are transmitted, i. e. as to whether 

 it was transmitted because there is a tendency for 

 acquired variations to be transmitted, owing to a power 

 the organism possesses to so affect its germ cells that 

 its acquired variations are reproduced in the offspring ; 

 or as to whether it was transmitted because this hap- 

 pened to be one of those very rare cases, those mere 

 coincidences, in which the force which produced the 

 acquired variation in the parent also produced directly 

 or indirectly such changes in the germs, as caused in 

 the organisms into which they proliferated inborn 



