488 THE HISTORY OF BIOLOGY 



ones and many insects exhibit similar [congruities. Even this protective 

 resemblance Wallace, of course, derives from natural selection. Furthermore, 

 he points out in this connexion the females' need for protection during the 

 period when they are ministering to their young as a cause of their less 

 conspicuous coloration, as in the birds, whereas the cock birds, which do 

 not require this protection, have developed greater splendour of colouring. 

 Wallace thus explains the external dissimilarity of the sexes without having 

 recourse to Darwin's theory of sexual selection, which he rejects. 



The whole of this theory of protective resemblance, which was once 

 cited as one of the strongest arguments in favour of Darwinism, has natu- 

 rally been discredited concurrently with the theory of selection itself; the 

 mimicry theory in particular had already been vehemently attacked by sci- 

 entists who did not find it accord with their observations and experiments; 

 the enemies that through their pursuit of prey were supposed to have called 

 for a protective resemblance have in many places been found to be non- 

 existent, and remarkable instances have been discovered of resemblances of 

 this kind in animals in different parts of the world, which could not there- 

 fore have influenced one another's appearance. Further, in order to maintain 

 the theory it has been necessary to ascribe to a great many animals powers 

 of observation and distinction as weak as man himself possesses. In the lat- 

 ter respect Wallace was extremely credulous; he states, inter alia: "The atti- 

 tudes of some insects may also protect them, as the habit of turning up the 

 tail by the harmless rove-beetles (Staphylinidas) no doubt leads other ani- 

 mals besides children to the belief that they can sting." This comparison 

 between the animal's power of observation in nature and that of a child is 

 certainly very naive. But Wallace was on the whole more of an imaginative 

 than critical nature; very soon he had astonished the world by becoming a 

 convinced spiritualist, although he was a free-thinker in religious questions, 

 and in later years he became entirely engrossed in spiritual seances and a 

 number of similar fantastic ideas of spiritual life in nature, while at the same 

 time he expressed his utter contempt for the results of modern heredity re- 

 search. He thereby placed himself definitely on the side of natural-scientific 

 development. 



A personality of an entirely different character was Darwin's other cham- 

 pion in England — Huxley, one of the most famous biologists of his time. 

 Thomas Henry Huxley was born in 182.5 in a London suburb, the son of a 

 poor schoolmaster. After two years at school, which he himself described 

 as "a pandemonium," he had from the age of ten to pursue his studies by 

 himself and he did so with such success that seven years later he gained an 

 entry into the medical faculty in London. Having passed his examinations, 

 he became a surgeon in the English fleet and served in that capacity in a 

 vessel that was exploring the channels north of Australia. In these tropical 



