160 HEREDITY. 



before the structure it produces. The structuring 

 cause Spencer calls organic polarity. I call it life. 

 As far as it makes use of facts, the third theory is 

 therefore, .at the last analysis, substantially the same 

 as the fifth. 



In the advance of microscopical investigation, we 

 are finding that the great discoveries of the last thirty 

 years concerning germinal matter have forced even 

 upon materialistic biologists, since Spencer wrote his 

 work, a new definition of life, and one approaching 

 yet more closely to that which has been defended 

 here. The latter, which may be called the established 

 definition, I call the Aristotelian also, for it expresses 

 Aristotle's idea that life is the cause of forms in 

 organisms. I hold in my hands a recent work repre- 

 senting fresh discussion by French materialists. This 

 volume has but just crossed the ocean. It is " Biolo- 

 gy," by Dr. Charles Letourneau, a book well known in 

 French, and translated now into English by Maccall, 

 and constituting the second volume of Chapman and 

 Hall's Library of Contemporary Science. Its discus- 

 sion has a materialistic trend, as any one will see 

 who opens at the strategic points. Always, when 

 you take up a volume on biology, turn to the chapter 

 on spontaneous generation. If any author believes 

 in spontaneous generation, he is behind the times. 

 Letourneau writes not without courage : — 



"We are compelled to admit that the first living 

 beings spontaneously organized themselves at the 

 expense of mineral matter. 



" The Darwinian doctrine, which results with such 



