636 ZOOLOGY SECT. 



of their origin. His speculations refer mainly to the modification, 

 or, as he calls it, degeneration, of domestic animals, and he sums 

 up his position as to the factors of the process by saying " the 

 temperature of the climate, the quality of nutriment, and the 

 ills of slavery, these are the three causes of change, of alteration, 

 and of degeneration in animals." In other words, he supports 

 the theory of the direct action of the environment. 



A bolder and more consistent evolutionist than Buff on was his 

 contemporary, Erasmus Darwin (1731- -1802), grandfather of 

 the author of the Origin of Species. As a competent critic has 

 said, ' he was the first who proposed and consistently carried out 

 a well-tounded theoiy with regard to the development of the 

 living world." In his Zoonomia, published in 1794-6, after 

 summarising the extraordinary adaptations to be seen in the 

 animal kingdom, he asks, " Would it be too bold to imagine that 

 all warm-blooded animals have arisen from one living filament 

 [he was a spermatist] which the great First Cause endued with 

 animality, with the power of acquiring new parts, attended with 

 new propensities, directed by irritations, sensations, volitions, and 

 associations ; and thus possessing the faculty of continuing to 

 improve by its own inherent activity, and of delivering down those 

 improvements by generation to its posterity, world without end ? ' 

 And a little later he inquires : " Shall we conjecture that one and 

 the same kind of living filament is and has been the cause of all 

 organic life ? ' He anticipated Lamarck in the importance he 

 attached to the principle of use and disuse, expressed his belief in 

 the inheritance of acquired characters, and recognised the import- 

 ance of sexual selection. 



The study of Zoology was also greatly advanced during the 

 eighteenth century by the voyages of Cook, Bougainville, and 

 others. New countries were explored, the peculiarities of their 



fauna? recorded, and valuable data accumulated for the studv of 



' / 



distribution. In this connection the names of Sir Joseph Banks, 

 Solander, and the two Forsters, all attached to Cook's expedi- 

 tions, of Sparrmann, and of Sir Hans Sloane may be specially 

 mentioned. The last-named was one of the greatest of collectors, 

 nnd the founder of the British Museum. 



The beginning of the nineteenth century was a period of great 

 zoological activity, distinguished by the work of some of the most 

 prominent leaders of the science. 



J. B. P. A. de Lamarck (1744-1829) was not only a distinguished 

 general zoologist and palaeontologist, but may also be looked upon 

 as the chief of the pre-Darwinian evolutionists. In his Philosophic 

 Zoologiquc, published in 1809, he completely rejected the idea of 

 the fixity of species, and endeavoured to explain the transformation 

 of one form into another by the operation of known causes ; of 

 these he attached most importance to the principle of use and 

 disuse, and he was a firm believer in use-inheritance. He was a 



