268 



'I iii:oRii':s ov mimicry 



enormous luimbcr of facts observed in many very 

 (litTcrent parts of the world. I Ix^lieve that the i^enerali- 

 zations will he admitted to be sound and to i)c well 

 warranted by the facts. Under any theory which is not 

 based upon selection, the whole of the facts on which 

 the ijfeneralizations rest become mere coincidences and 

 receive no explanation of an\- kind. Under Natural 

 Selection this vast body ot facts becomes at once in- 

 tf'llivible. Mere the accumulated facts of the most 

 diverse kind, which receive an intelli^i])le explanation 

 by the theory in (juestion, )ield a firm support to the 

 theory. There are many theories which are held upon 

 indirect evidence of precisely the same nature. We 

 believe in evolution, not because we see it takinc^ place, 

 but because of the immense number of observed facts 

 which it renders intellii:ible. 



lu the case of Natural Selection in relation to Mimicry 

 and Common Warnini^ Colours it is to be confidently 

 ho|)ed that direct evidence may yet be added ; indeecl, 

 a considerable amount is even now forthcomini^. Pro- 

 fessor Lloyd Morgan's work ^ upon the activities and 

 instincts of youniL^ birds of many species, proves that 

 their education is actually of the kind which is pre- 

 sui)posed in the theories of H. W. Bates and Fritz 

 Miiller. \\c, shows that they have no instinctive know- 

 ledge of things which are good for food, but that they exam- 

 ine and test everything. On the other hand, they have 

 excellent memories, and retain a firm impression of the 

 appearance of objects which have given them an un- 

 l)leasant experience. Furthermore, there was evidence 

 that they are influenced in their behaviour towards 

 other objects r(\sembling the one which has proved ob- 

 jectionable to them. As to the aggressive Hymeno- 

 ptera, the evid(!nce of their special methods of defence 

 is obvious to ever\ one. \\ ith regard to specially pro- 

 tected groups of butterllies there is a large amount of 

 evidence from observation and experiment, but more is 

 to be desired. bOr j)ositive results I may refer to Guy 



' Ilaliit and Iiisiiuct, London. 1896. 



