ADVERTISEMENT. iu 
mon May chaffer, so extremely plentiful throughout the British 
Islands. 
I have been fortunate, too, in the course of subsequent researches, 
in naving arrived at the true solution of a problem, which has greatly 
puzzled every natural historian ; and have erroneously stated, at page 
192, that the extraordinary habit of the cuckoo, in invariably entrust- 
ing its egg to the charge of other species of birds, is not to be 
accounted for upon any structural peculiarity.'' Let it here suffice, 
that this depends primarily on a peculiarity of the vascular system 
(first intimated to me by my esteemed friend Mr. Yarrell), and more 
particularly on the comparative minuteness of those blood-vessels 
which supply the generative parts ; in consequence of which — of the 
small portion of blood thereto determinated — these organs, as well as 
the egg, are most disproportionately small for the size of the species ; 
and, what is more to the present purpose, each successive egg requires 
a much longer time (I believe full two or three weeks) to attain its de- 
velopment ; wherefore it is clear that under these circumstances the 
species could but ill manage to incubate its own. Let it be observed, 
that all the habits of this interesting bird are in accordance with the 
foregoing explanation of the structural cause of its peculiarities. 
In submitting the various additional observations on British Natural 
History, interspersed through this volume, to the wished-for impartial 
judgment of the world, it is hoped that they will at least find favour 
for their originality. Should they prove to be of any assistance to 
those who are engaged in studying the natural productions of our 
island, my principal object in penning them will be amply recom- 
pensed. 
For the interesting account of Selborne in its present state, we are 
indebted to the elegant pen of Mr. Mudie, whose enthusiasm in the 
cause of natural science led him to visit Selborne in the autumn of 
the present year. We are also indebted to Mr. Dixon, who visited 
the village in 1835, for some interesting notes to the Antiquities. 
EDWARD BLYTH. 
Lower Tooting, 
Wov. 1836. 
