^6 BIOLOGICAL LECTURES. 



Our palaeontological series are unique in being phyletic 

 series. They exhibit no evidences of fortuity in the main 

 lines of evolution. New structures arise by infinitesimal be- 

 ginnings at definite points. In their first stages they have no 

 ' utilitarian ' or ' survival ' value. They increase in size in suc- 

 cessive generations until they reach a stage of usefulness. In 

 many cases they first rise at points which have been in maxi- 

 mum use, thus appearing to support the kinetogenesis theory. 

 In extensive fossil series we also find evidence of anomalous or 

 neutral variations, such as Bateson has brought together, but 

 these are aside from the main lines of evolution. They pre- 

 sent no evidence for the Neo-Darwinian principle of the 

 accumulation of adaptive variations out of the fortuitous play 

 around a mean of adaptive and inadaptive characters, but they 

 present strong evidence of the Darwinian principle of the sur- 

 vival of the fittest. The main trend of evolution is direct and 

 definite throughout, according to certain unknown laws and 

 not according to fortuity. This principle of progressive adapta- 

 tion may be regarded as inductively established by careful 

 studies of the evolution of the teeth and the skeleton. Its 

 bearing upon Lamarck's factor of the transmission of somato- 

 genic variation was pointed out by myself in 1889 ; it does not 

 positively demonstrate Lamarck's factor because it leaves open 

 the possible working of some other factor at present unknown, 

 and Lamarck's factor is also inadequate ; but it positively sets 

 aside Darwin's factor as universal in the origin of adaptations 

 and as a consequence 'the all-sufficiency of Natural Selection.' 

 If Lamarck's factor is disproved, in other ways, it leaves us hi 

 vacuo so far as a working hypothesis is concerned. 



The conclusions which Hyatt, Dall, Williams, Buckman, 

 Lang, and Wiirtemberger have reached among invertebrates are 

 independently paralleled by those of Cope, Ryder, Baur, Scott, ^ 

 the writer, and many other morphologists. The same general 

 philosophical interpretation of evolution is now independently 

 announced from an entirely different field of work by Driesch. 

 We may waive our applications of these facts to theories, but 

 let us not turn our backs to the facts themselves ! 



1 W. B. Scott : On Some of the Factors in the Evolution of the Mammalia. 

 Journ. of Morphology, vol. V, 1891, p. 378. 



