140 THOMAS HENRY HUXLEY 



6. Influence of a Changing Environment in Modifying 

 Organisms. Climate, Station and Hybridization recog- 

 nized before the time of Treviranus. Use and Disuse, 

 advanced as factors by Lamarck. Ultimately Darwin's 

 theory of Natural Selection. 



7. Geographical Distribution, Darwin and Wallace. 



8. Geological Succession, Darwin and Wallace. 

 Riitimeyer, Kowalewsky, Marsh, and Huxley. Work 

 on pedigrees of Mammals and Crocodiles. 



The strongest evidence in favour of Evolution afforded 

 by 7 and 8. 



Two important books also appeared in 1 877, i.e., 

 Physiography and The Anatomy of Invertebrated Animals. 

 The former embodies the preliminary lectures which 

 Huxley had given for some sessions as an introduction to 

 his regular course (see p. 37), and of which the Thames 

 basin furnished the main theme. This work had an ex- 

 tensive circulation for many years, and a judiciously edited 

 revised edition has recently been put before the public. 

 With the intention, apparently, of encouraging the 

 teaching of general principles as laid down by Huxley, 

 the Science and Art Department added " Physiography " 

 to their list of subjects, the first examination being held 

 in May 1878. The result was unfortunate, for the 

 syllabus was conceived in a singularly unscientific spirit, 

 and consisted of an extraordinary aggregate of disjecta 

 membra. The subject, indeed, was about as unscientific 

 as the " General Elementary Science," of which so much 

 has been heard during late years. But we must re- 

 member that it belongs to the time when any degree of 

 any British University qualified its possessor to earn 

 Government grants in any science or pseudo-science 

 subject, from Pure Mathematics and Naval Construction 

 to the Principles of Agriculture. 



