70 PROGRESS OF SCIENCE 



particularise more closely) in the study of the dis- 

 tribution of plants ; Huxley in that of morphology. 



The whole period, down to Darwin's time and 

 after, was one in which many great zoologists and 

 botanists were also great travellers : Brown, Darwin 

 himself, and Hooker studied their subjects in many 

 lands, and among other names that of A. R. Wallace 

 stands out. And the same is true of students in a 

 special field peculiarly appropriate to Britain and sup- 

 ported from its early years by the British Association 

 that of marine biology. Prom 1840 onward, with 

 the support of the Association, Edward Forbes was 

 at work in the Aegean Sea and elsewhere ; and the 

 Association had a share in promulgating the culmi- 

 nating expedition for the study of the sea which was 

 carried out on board H.M.S. Challenger in 1 872-76. l 

 A recent movement in favour of another such ex- 

 pedition, originated in the Association (1920), is no 

 more than delayed, it may be hoped, by the un- 

 favourable condition of national finance. Indeed 

 the work of the travelling biologist, whether at sea 

 or on land, is far from finished yet, and even the 

 brief visits of the Association overseas have afforded 

 notable opportunities in this direction. 



The question of variations in nature tending 

 toward the so-called survival of the fittest was of 

 course studied before Darwin's day, and modifica- 

 tions of his views have been introduced since. 

 Sudden and marked variation, for example, has been 

 recognised rather as a normal than as an extraordinary 

 process, when such variation proves itself better 

 capable of survival than the parental type. With 



1 See, further, pp. 196, 228. 



