Birds. 



6141 



animal of its natural scent is established. All substances partaking of 

 the nature or pro]jerUes of either musk or ammonia must be, if present 

 on any part of an animal's skin or coat, and exposed to any diffusing 

 agency, liable to betray themselves, whether the animal wishes it or 

 not, to the first passer by possessing suitable olfactory powers. The 

 only control it can have over them depends upon its perfect immo- 

 bility, as by that course it is saved from putting the air immediately 

 surrounding it and most impregnated with its scent into motion ; and 

 so from diffusing the odorous particles or vapours through a wider 

 extent of the suspensory medium. With this remark I close the 

 present paper. 



J. C. Atkinson. 



Danby Parsonage, Giosmont, York, 

 March, 1858. 



While Thrushes^ BlacJcbirds, ^c. — Tn a funner number of the ' Zoologist' I sent 

 you a paper on ihe transmission of colour by white and pied pheasants, wherein I 

 stated the great numbers here which had been bred originally from one white cock 

 pheasant ; and I now venture to trouble you with a Anther communication as to the 

 vagaries of Nature at the same place, with reference to the colours of other birds and 

 animals. First as to thrushes : — Last year two white specimens were found in the 

 neighbouring ])arish by a boy, who has brought up one of them, which is now alive, 

 sings, and is doing well ; the other was taken out of a different nest, and I beHeve is 

 since dead. This year, within about half-a-niile of v^here the former birds were taken, 

 in some very secluded ornamental walks down a rocky dell or dingle, with a series of 

 po(ds occupying the bottom of it, a blackbird's nest was found, and unfortunately 

 taken ; one at least of its young inhabitants was captured, which proved to be 

 completely white ; another, which luckily escaped, was quite grey or pied, and nearly 

 the colour of a young cuckoo. These varieties in blackbirds are not very uncommon 

 occurrences in different parts of the kingdom, but those of the thrushes are, T believe, 

 very unusual. My next variety was in a young rook. When the young rooks are 

 strong enough to leave their nests, a great onslaught upon them takes place here for 

 a few days by the butler and groom, to keep them within a reasonable quantity ; and 

 at a neighbouring rookery, a few hundred yards distance, on another gentleman's 

 property, some young friends told me the other day they had that morning killed 

 between eighty and ninety young rooks ; but notwithstanding this havoc son)e consi- 

 derable number of the young rooks get away, and amongst others who came here for 

 safety, I saw one, the whole of which, excepting the wings and head (which were 

 black), was of a dun colour, and as nearly as possible had the appearance of a hooded 

 or royston crow (as it is often called) ; but it was unquestionably a young rook, and 

 in company with several old ones. The fourth example of an unusual colour are 

 rabbits, which in this dry and heathy soil arc so prolific that a rabbit-catcher is 



