vi PREFACE. 
class. I was, of course, delighted at getting a recruit for Natural History of 
such energy and ability. JI may mention here that amongst other questions 
which I asked him at this interview was whether he knew German, as without 
a knowledge of that language it would be impossible for anyone in these days 
to do good work in Natural Science. Sir Victor in reply regretted his 
ignorance of this language, but stated that he should set to work and learn it 
at once. A few months afterwards I found to my surprise that he had 
kept his word, and was already abie to translate passages in the German 
authorities to which he had occasion to refer. I may add that I have given 
the same advice more than once to other would-be students of Natural 
History, but that I never recollect it having been followed with such 
immediate and successful results. 
From my position at the Zoological Society and from the aid received from 
numerous correspondents in all parts of the world, I had little difficulty from 
the first in providing my much-esteemed friend with materials for his studies, 
and in the beginning of 1871 had the pleasure of putting at his disposal 
some notes and materials concerning the Antelopes of the genus Tragelaphus. 
Upon these was based the excellent paper on that genus read by Sir Victor 
before the Zoological Society on the 16th of May of that year, the first of a 
series of essays on this and kindred subjects. Four similar papers, as will be 
seen by reference to the Zoological Society's ‘ Proceedings,’ followed in 1872, 
three in 1874, and others in succeeding years, until 1878, when, I regret to 
say, they came to an abrupt conclusion. ‘The last of the series was one of an 
extremely useful and important character, containing, as it did, a complete 
essay on the classification of the Deer-family and a synopsis of the existing 
species, which, until recently, has remained our leading authority upon this 
difficult group of Mammals. During the whole of this time also Sir Victor 
had been engaged in collecting specimens, and in having drawings made by 
Wolf and put upon the stone by Smit, for a complete work on the Bovine 
animals which he had planned out and proposed to write. After 1878, 
