EMBRYOLOGY AND EVOLUTION 



and its main course; the latter determines which of these 

 possibilities are realized and modifies more or less the course 

 of development. 



Entirely similar causes are at work in the evolution of races 

 or species. With true insight Charles Darwin wrote, many 

 years ago: "Although every variation is either directly or 

 indirectly caused by some change in the surrounding condi- 

 tions, we must never forget that the nature of the organiza- 

 tion which is acted on essentially governs the result." 

 Whether these variations are first wrought in mature organ- 

 isms and then transferred in some unknown way to the 

 germ cells, as Lamarckians assert, or whether they first 

 appear in the germ cells, as Weismann and his followers 

 maintam, is a secondary, although important, consideration, 

 into which we will not enter here. In conclusion it may be 

 confidently asserted that the causes or factors of the evolution 

 of species and of the development of an individual are 

 fundamentally the same. 



Development, Evolut'ioti, and Religion 

 What bearings do these scientific evidences as to the origin 

 of individuals and species have on religious faith? It might 

 satisfy our pride to believe that every human being sprang 

 into existence fully formed and armed, like Minerva, from 

 the brain of Jove, but however pleasing such a belief might 

 be it could not be held by sane and enlightened people. We 

 know well that every human being, even the greatest that 

 ever trod the earth, was once a baby, an embryo, a germ cell, 

 and this knowledge has not destroyed our belief in the dig- 

 nity of man nor in the existence of God. 



It pleases many persons to believe that the first man 

 sprang into existence fully formed and perfectly endowed, 

 coming directly from the hand of God by an act of super- 



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