of taking an Ornithological Census. 193 



unvaried notes of the Chiff-chaff are as commonly heard as the 

 joyous song of the Willow Wren^ while, in the parish in which 

 I am writing, the latter bird outnumbers the former by many 

 hundreds to one; or why, again, in some of the northei*n coun- 

 ties the Wood Warbler is nearly as numerous as the Willow Wren, 

 while here it is not more common than the Chiff-chaff? Of 

 course the ready reply is, " Oh, it is owing to the difference 

 in the habits of the species, and in the character of the locality." 

 But this is really no answer ; for immediately I rejoin, what are 

 those differences ? and, at present, I have no means of gratifying 

 my curiosity on this point. Nor will, I suspect, a satisfactory an- 

 swer be found until we have reliable information not only as to 

 the approximate proportion which the species I have named bear 

 to each other in different districts, but also as to the relative 

 abundance of other species which influence their existence. This 

 opens a wide region for inquiry, wherein not only the student of 

 other branches of zoology, but also the botanist and the geolo- 

 gist must help us ornithologists, and accordingly the object of 

 my communication to the Linnean Society is to invite such 

 assistance. 



I regret extremely that among Mr. Wolley's papers I can find 

 few memorandums or suggestions bearing on the subject, and 

 yet I know that towards the close of his life it occupied his 

 thoughts not inconsiderably. He first acquainted me with his 

 idea in a letter from Ormoga in (Eland, dated June 7, 1856, in 

 which he stated, that at the meeting of Scandinavian naturalists, 

 which he was then about to attend, he should like to "give 

 some account of the British birds, of which so little is known 

 on the Continent beyond the bare list." He wished to begin 

 "by naming the birds which are commonest in England and 

 most characteristic of our bird-fauna ;" above all, " to be able to 

 represent by numbers the relative abundance of each species : 

 throughout Great Britain put a Sparrow at 1,000,000, and an 

 Osprey at 1, what will be the intermediate figures ? " As may 

 be readily imagined, I was unable to supply him with any facts 

 that he could use, and consequently his design was abandoned, 

 but, as I trust, only to be taken up and completed some day by 

 the numerous ornithologists of this country. However, I had 



