of taking an Oy-nithological Census. 191 



requirement of British ornithology. To this opinion I cannot 

 entirely consent; but I nevertheless think that if some such 

 approximate estimate could be made, it would be extremely ad- 

 vantageous not only to English ornithologists, but to those of 

 foreign countries ; and that, if more generally extended to other 

 branches of natural history, it might furnish results of a very 

 valuable, not to say unexpected, character. 



Just at this time, when we are on the eve of taking the human 

 census of the British Empire, I think, then, it is not inappro- 

 priate to bring a somewhat similar design as regards our Fauna 

 to the notice of naturalists. With this view I am about to com- 

 municate to the Linnean Society some remarks bearing upon 

 the question of a general zoological census, while I here propose 

 more especially to call the attention of ornithologists to the 

 particular application of Mr. Wolley's project. 



I am not so sanguine as to hope that any immediate steps 

 will ensue from this paper ; but if my brother-students will but 

 lend the matter their consideration, perhaps, before the close of 

 the existing generation, we — or, rather, our successors — may be 

 in a position fairly to begin the work. Indeed, beyond stating my 

 conviction that a census of our birds merely can only be taken 

 by the co-operation of nearly all the ornithologists in the 

 country, I am not at present prepared to offer any suggestions 

 as to the method to be employed. But I wish to make a few 

 observations on the subject. 



Now as to the probable utility of such a census, to which I 

 imagine many will at the outset demur. It is unnecessary in 

 these days, if it ever was otherwise, to show how much light has 

 been thrown upon natural history by an understanding of the 

 geographical distribution of species. Yet our acquaintance with 

 this extensive field of research is very limited. The six great 

 physical regions of the earth^s surface have been defined with 

 more or less accuracy, but the details are far from being filled 

 in. Meritorious efforts have been made to determine the summer 

 range of the Nightingale and the lines of the Crane's simultaneous 

 arrival. The progressive advance of the Republican Swallow in 

 North America, of the Grey Partridge in Scandinavia, and of the 

 House Sparrow in Siberia has been recorded. The respective 



