ROOKERIES 303 



inspires disgust. Still I am not sure that as regards 

 the welfare of the species the practice is detrimental. 

 It reduces the number of mouths to be fed and the 

 survivors must consequently thrive in proportion. If 

 there was no Rook-shooting we should doubtless have a 

 large emigration of young Rooks in autumn, and a 

 very small number of the emigrants would return in the 

 spring. As it is the emigration is hardly perceptible, 

 perhaps being no greater than the immigration in 

 spring. 



The varied fortune of rookeries is indeed very 

 curious, and their waxing and waning would be a 

 wonderfully interesting subject to investigate ; of 

 course, in almost every case the supply of food is the 

 turning-point. We have, as I dare say you know, an 

 abundance of Rooks here, not, I am sorry to say, in the 

 garden of this College ; but from St. John's to Downing 

 is an almost continuous rookery so far as the presence 

 of trees admit. When I first knew Cambridge T think 

 there were two distinct establishments ; that in the 

 Johnian " wilderness," and that in the trees fronting 

 Cat's Hall. The former has spread in extent, though I 

 am not sure there are more birds, partly owing to many 

 trees having been blown down, and the latter certainly 

 has more nests than it used. There are nests at 

 intervals all along the backs of the Colleges as far as 

 Queen's ; so that really, as I have said, there is scarcely 

 any breach of continuity. Downing, too, is but a skip 

 and a flutter from Cat's, and since the Downins^ trees 

 have grown up. Rooks have taken to them immensely. 

 There is also a nest or two in the garden of Caius though 

 quite surrounded by buildings, and some at Sidney. I 

 wish we had some in our grounds, but I suspect our 

 trees are not to their liking. 



July 24, 1879. 



My dear Lilford, 



I had nearly omitted to notice your kind 

 offer of Flamingoes' eggs, for which I thank you much ; 



