30 PROCEEDINGS OT THE 



j)roveil to have advanced bryoiul his iiniiiediato prodcHossor in at 

 least one iini)ortant cbaracter, bnt in liis iniinatnro state he 

 rtHains that character in a slij^litly nioditied form. 



The paheontolot^ist, therefore, is convinced that whenevei* he is 

 able to trace lineai^es he finds evidence of the recapittdation of 

 ancestral cliaracters in eacli life history; and he fails to appreciate 

 the snbtleties of logic of those who argue the question from the 

 comparatively narrow standpoint of the study of existing life. 

 lie is oqnally convinced that the phenomena he observt'S wiien 

 tracing lineages can only be explained by assuming that acquired 

 characters are inherited, lie finds a gradual advance towards 

 complete harmony \\ith the enviromnent in successive forms — 

 adaptations to snillciency of feeding, to effectiveness in locomotion, 



rig. 1. 

 A B 



ccam OoDcoO 



D 



Dia<jrainiriatic front views of the lower incisors and eaniiie teeth, sliowing tliat 

 if the milk dentition of modern Man (a) were modified by the complete 

 extrusion of the caniiips (n), this would resemble tiie permanent dentition 

 of Piltdown fossil Man (c) more closely than does tiie permanent 

 dentition of any Ape, such as the Chimpanzee (d); three-quarters nat. 

 size. 



and so forth ; and it is difficult to believe that these steps forward 

 are not influenced by the struggle of successive generations with 

 the conditions under whicli the}' live. Kanimerer'.s experiments 

 on living animals are said to prove tliat newly acquired characters 

 are not always inheriled in the same manner as more deeply 

 ingrained characters — that, in fact, they differ in not fulfilling the 

 ^lendelian (expectation. A pahTontologist, studving lineages, will 

 welcome this result if it can he sid)stantiated, for he often notes 

 rhythm in evolution — uneciual rates of progress — which mav 

 imply that under certain circumstances some characters may need 

 repeated acquisition in a longer series of generations than others 

 before they become part of the permanent inheritance. 



