IV PREFACE. 



favoured with more papers on Mammals, Fishes, Keptiles, 

 Mollusca, and Crustacea, they would be gratefully received, and 

 much good would no doubt result if some of our contributors 

 would occasionally turn their attention to other branches of 

 Zoology than that with which they are most familiar. Kemem- 

 bering the old adage " docendo discimus" they would derive a 

 new pleasure from the investigation of a new subject, and their 

 researches might lead to the discovery of novel and perhaps 

 important facts. And here a suggestion may be hazarded. 

 During the past year the Editor has received a number of 

 letters pointing out the inadequacy at the present day of 

 Bell's * British Quadrupeds' as a text-book (a fact of which 

 he has long been cognizant), and urging the desirability of 

 preparing something better. As a matter of fact, ever since 

 1874, when the second edition of Bell's work was published, 

 the Editor has been engaged in collecting materials with a view 

 to meet the demand which is now being made. These materials, 

 however, are still far from complete, and although the number 

 of British Mammals is comparatively limited, there are still 

 many points upon which trustworthy statistics are wanting. For 

 example, the period of gestation in certain species, their rate of 

 growth, the average age which they attain, their weight, and 

 measurements, taken from living or recently-killed specimens, 

 their habits of migration and hibernation, the cause of variation 

 in colour, of albinism, melanism, and so forth. On all these 

 points there is still much to be ascertained, and those who can 

 forward statistics will materially assist the preparation of such 

 a new work as is now needed. There is no doubt that in the 

 forty-eight volumes of * The Zoologist ' which have been pub- 

 lished information is to be found on many of these points, 

 but the want of a "General Index" makes the search for it 

 extremely laborious. We have on former occasions called 

 attention to this want, and we may again remind our readers 

 that as the cost of preparing and printing a "General Index" 

 would be considerable, it would not be expedient to undertake it 

 unless every reader of * The Zoologist ' were to signify his or her 

 willingness to take a copy of it when published. So long as 

 there continues to be a hesitation to support the undertaking, 

 so long, we fear, will a " General Index" remain unpublished. 

 Verba in %wp % 



