xxvi 



organs of vertebrates are the derivatives of the segmental organs of 

 Vermes, thus fcrging a strong link in the chain which holds together 

 all animal life. Of still wider import, and perhaps still greater value, 

 was his elaboration of views, begnn in his apprentice work on the 

 Primitive Streak, and continued even into those last investigations 

 which his sad death left unfinished, on what may be spoken of as the 

 general formation of the complex animal bodies, and especially on 

 the relation of the alimentary canal to other parts. Balfour early saw 

 that certain vanishing grooves and holes and burrows in the embryos 

 of higher vertebrates were the traces of the ways in which these 

 higher forms had been evolved from lower ones, and all his work 

 through he left no stone unturned, i.e., no specimen or section un- 

 searched, in his efforts to fill up gaps of evidence, and thus to make 

 the whole story clear. 



The same guiding principle, the same logical method, the same 

 clear distinction between the proven and the probable are also seen 

 in his remarkable memoir on the Spinal Nerves of ElasmobrancliF j 

 (which threw almost as much light on the genesis of the vertebratej 

 nervous system as his earlier work did on the urogenital organs), anr'jfl 

 indeed, are conspicuous in every one of his separate papers, includir J 

 the unfinished fragments on Peripatus, as well as in every page of thl 

 incomparable " Comparative Embryology." He was unwearied in hm 

 labours, sitting for hours together preparing and examining sectic^| 

 after section; bnt others have been as unwearied as he. To him 

 belonged that part of genius, which kept him from being buried 

 beneath accumulated facts, and gave him the power to seize at once 

 upon the new salient fact as soon as it appeared, to develope its 

 meaning, and to carry its teaching home to others by solid irre- 

 fragable reasoning. 



Balfour will be known hereafter as a brilliant morphologist, as one 

 who busied himself with high questions of theoretic import ; but there 

 was also another side to even his biologic character. Much of the pro- 

 gress of biology has been due to the labours of men to whom perhaps 

 more rightly belongs the title of naturalist ; men who often do not vex 

 themselves with the more abstract problems of morphology, but born 

 with an innate love of living things, quietly gather facts and work 

 out truths, putting together their results in the guise for the most 

 part of some taxonomic inquiry. Naturalists of this stamp are 

 generally born such, not made, whereas a man of adequate mental 

 strength may become an accomplished morphologist without feeling 

 any real sympathy with concrete animal life ; he may be carried on 

 by the mere interest of purely intellectual questions. Now Balfour, 

 like his master, Darwin, w r as a born naturalist ; his knowledge and 

 appreciation of the concrete characters of the individual were as 

 striking as the power which he displayed in dealing with abstract 



