90 SECTIONAL ADDRESSES. 



type, as, for instance, when Przibram himself shows that the length of a 

 rat's tail is a function of the temperature to which the individual and its 

 immediate progenitors have been exposed. As for the inheritance of 

 impressed modifications, the more unequivocal the experiments devised to 

 demonstrate its reality the more clearly do they show it to be of so fugitive 

 a kind as to have no significance in evolution. Palaeontologists, as Dr. 

 Bather has told us, have proved beyond the possibility of doubt the 

 occurrence of parallel and even of convergent evolution, without telling us 

 where we are to stop in applying the principle. Many supposed examples 

 of adaptation fail to stand closer scrutiny, and therefore the whole idea of 

 adaptation is declared to be a subjective illusion. All these results at any 

 rate place no obstacles in the way of Prof. Przibram's suggestion. 



It is to be noted that although the theory of Apogenesis is called a 

 theory of evolution, it does not deal at all with evolution as that word was 

 used by Darwin. It has nothing to say on the origin of species. On 

 this question it is no more than a doctrine of special creation at one 

 remove. It has no light to throw on classification. If we are to 

 abandon belief in community of descent the whole architecture of the 

 Systema Naturae becomes meaningless. 



Prof. Przibram claims that ' all the facts would be explained more 

 easily ' upon his hypothesis, but there is one point on which he speaks with 

 a hesitant voice, and it seems to me a very significant exception. ' We 

 cannot decide ' he says, ' whether the differing though related species that 

 inhabit islands or isolated territories are descended from a common source 

 or result from the accidental separation of species which formerly occupied 

 the region together.' 



Let me recall to you the opening words of the ' Origin of Species.' 

 ' When on board H.M.S. " Beagle " as naturalist, I was much struck with 

 certain facts in the distribution of the organic beings inhabiting South 

 America, and in the geological relations of the present to the past inhabi- 

 tants of that continent.' So Przibram ends where Darwin began. The 

 geographical and geological distribution of organisms, which for the one 

 are merely the negligible residue of unexplained facts, were for the other 

 the very heart and core of the problem he set himself to consider. 



It is worth remembering that among Darwin's other qualifications as an 

 interpreter of nature, he was an experienced taxonomist, and before he 

 wrote ' The Origin of Species' he had produced one of the finest systematic 

 works ever written in his ' Monograph of the Cirripedia.' Those of us who 

 were present at the memorable Darwin-Wallace celebration of the Linnean 

 Society in 1908 remember how the veteran Alfred Russel Wallace discussed 

 ' the curious series of correspondences both in mind and in environment ' 

 which led Darwin and himself, alone among their contemporaries ' to 

 reach identically the same theory,' and how he gave the first place to the 

 fact that both he and Darwin began by collecting beetles and thus acquired 

 ' that intense interest in the mere variety of living things ' which led them 

 to speculate upon the ' why ' and the ' how ' of ' this overwhelming and, 

 at first sight, purposeless wealth of specific forms among the very humblest 

 forms of life.' It might be worth while to inquire whether a training that 

 proved useful to Darwin and to Wallace would not be of some value to 

 students of zoology even at the present day. 



