DARWINISM DEFENDED. '85 



7 Dohrn, Anton, "Der Ursprung der Wirbeltiere urrd das Princip 

 des Functionswechsel," 1875. 



8 Cope, E. D., 'The Energy of Evolution," Amer. Nat., VoL 

 XXVIII, p. 205, 1894. I quote the following: "In considering the 



dynamics of organic evolution, it will be convenient 

 Cope's proof J , . . 



that natural to commence by considering the claims of natural 



selection cannot selection to include the energy which underlies the 

 make new char- process. That natural selection cannot be the cause 

 acters, Q ^ or ig m o f new characters, or variation, was 



asserted by Darwin,* and this opinion is supported by the following 

 weighty considerations. 



"(i) A selection cannot be the cause of those alternatives from 

 which it selects. The alternatives must be presented before the 

 selection can commence. 



"(2) Since the number of variations possible to organisms is 

 very great, the probability of the admirably adaptive structures 

 which characterise the latter having arisen by chance is extremely 

 small. 



"(3) In order that a variation of structure shall survive, it is 

 necessary that it shall appear simultaneously in two individuals of 

 opposite sex. But if the chance of its appearing in one individual 

 is very small the chance of its appearing in two individuals is 

 very much smaller. But even this concurrence of chances would 

 not be sufficient to secure its survival, since it would be immediately 

 bred out by the immensely preponderant number of individuals 

 which should not possess the variation. 



"(4) Finally, the characters which define the organic types, so 

 far as they are disclosed by palaeontology, have commenced as 

 minute buds or rudiments, of no value whatsoever in the struggle 

 for existence. Natural selection can only effect the survival of 

 characters when they have attained some functional value. 



"In order to secure the survival of a new character, that is, of 

 a new type of organism, it is necessary that the variation should 

 appear in a large number of individuals coincidentally and suc- 

 cessively. It is exceedingly probable that that is what has occurred 

 in past geologic ages. We are thus led to look for a cause which 

 affects equally many individuals at the same time, and continuously. 

 Such causes are found in the changing physical conditions that have 

 succeeded each other in the past history of our planet, and the 

 changes of organic function necessarily produced thereby." 



9 Piepers, M. C, "Thesen iiber Mimikry," Verh. Internat. Zool. 

 Cong., p. 350, 1902. 



* "Origin of Species," ed. 1872, p. 65. 



