BY HEBER A. LONGMAN. 33 



of the appearance of neA\ structures seems to be the basis 

 of the theory of atavisiu/'* Stapler ilhistrates this stand 

 point by demonstrating that where neck ribs have degener- 

 ated into vestiges in certain cases they have re-evolved in 

 response to a different impluse. Doubtless many structures 

 once traced to atavistic influences are in reality new. 

 Here we may appropriately note that Hans Gadow 

 in his presidential address to the Zoological Section 

 of the British Association last year gave a most 

 useful summary of both facts and nomenclature associated 

 ^vith the old terms of convergence and parallelism. 



Then. too. there are evidences of the exuberance of 

 life for which we need seek no causal explanation. Darwin 

 was content to look upon certain )nanifestations as being 

 incidental and unimportant. In the " Descent of Man "f 

 he says : " Bearing in mind how many svibstances closely 

 analogous to natural organic compounds have been recently 

 formed by chemists, and which exhibit the most splendid 

 colours, it would have been a strange fact if substances 

 similarly coloured had not often originated, independently 

 if any useful end thus gained, in the complex laboratory of 

 living things." Bateson says,| "1 feel sure that we shall 

 be rightly interpreting the facts of nature if we cease to 

 expect to find purposefvilness wherever we meet with 

 definite structures or patterns." Starr Jordan, when 

 writing of the bright colours of coral fishes, says that these 

 cannot be explained on protective lines, and that nature 

 seems to revel in bright colours when it is safe for her 

 creatures to have them. Dendy instances the sculptured 

 patterns on the calcareous shells of Foraminifera as charac- 

 ters which are of no adaptive value and which might be 

 equally well replaced by alternative characters. These 

 patterns are of a specific nature, but he cogently asks, "" Does 

 one pattern help a unicellular foraminiferan or radiolarian 

 more than another in the struggle for existence ? "** The 

 theories of warning, protective, adaptive and sexual colour- 

 ation and recognition marks account for a large proportion 



*Pro. Roy. 8oc.. Vic, XXV. .PL I., Auu., Iltl2. 



+2nd E(]itic>n. ]<. 2(>2. 



X" Darwin and Modern Science," p. 100. 



**" Outlines of Evolutionary Biology," p. 410. 



