Natural Histm-y in the English Counties, 473 



and which have not before been figured in any botanical work. Besides the 

 descriptions of new or rare plants, the author has given details respecting 

 their uses and cultivation. {Oversigt over det Danske vidcnskab. Sckkabs 

 forhandl.) 



ASIA. 



Vision of Birds of Prey. — It always appeared to us most extraordinary, 

 indeed unaccountable, that birds of prey could scent carcasses at such 

 immense distances as they are said to do. We were led to scepticism on 

 this subject, some twenty years ago, while observing the concourse of birds 

 of prey, from every point of the horizon, to a corpse floating down the river 

 Ganges, and that during the north-east monsoon, when the wind blew stea- 

 dily from one point of the compass for months in succession. It was ex- 

 tremely difficult to imagine, that the effluvia from a putrefying body in the 

 water could emanate in direct opposition to the current of air, and impinge 

 on the olfactories of birds many miles distant. Such, however, were the 

 dicta of natural history, and we could only submit to the general opinion. 

 We have no doubt, now that we know the general opinion to be sometimes 

 wrong, that it was by means of the optic, rather than the olfactory, nerves, 

 " that the said birds smelled out their suit." 



The toucan is a bird which ranks next to the vulture, in discerning, 

 whether by smell or by sight, the carrion on which it feeds. The immense 

 size of its bill, which is many times larger than its head, was supposed to 

 present, in its honeycomb texture, an extensive prolongation of the olfactory 

 nefve, and thus to account for its power of smelling at great distances. 

 But, on accurate examination, the texture above mentioned in the bill is 

 found to be mere diploe to give the bill strength. Now the eye of this bird 

 is somewhat larger than the whole brain, and it has been ascertained, by 

 direct experiments, that where'very putrid carrion was enclosed in a basket, 

 from which effluvia could freely emanate, but which concealed the offal 

 from sight, it attracted no attention from vultures and other birds of prey, 

 till it was exposed to their view, when they immediately recognised their 

 object, and others came rapidly from different quarters of the horizon, 

 where they were invisible a few minutes before. 



This sudden appearance of birds of prey from immense distances, and in 

 every direction, however the wind may blow, is accounted for by their 

 soaring to an altitude far beyond our sight. In this situation, their prey on 

 the ground is seen by them, however minute it may be, and therefore their 

 appearance in our sight is merely their descent from high regions of the 

 atmosphere to within the scope of our optics. The toucan, in India, gene- 

 rally arrives a little in the rear of the vulture, and remains till the larger 

 bird is glutted, while smaller birds of prey, at a still more retired distance, 

 pay similar homage to the toucan. {Dr. James Johnson, in Medico-Chirurg. 

 Review.) 



Art. II. Natural History in the English Counties, 



Middlesex. 



The ChiJ^-chaJ' arrives among the first of our summer birds, about the 

 latter end of April, and may be seen moving briskly from right to left in the 

 top branches of some tall tree, calling the peculiar note from which it re- 

 ceives its name. I send you one for inspection which was lately shot in 

 this neighbourhood. — A Constant Header. Sept. 15. 1829. 



We have sent the specimen, for which we return our best thanks, to Mr. 

 Sowerby's museum ; Mr. Sowerby says it is the Lesser White Throat (Mo- 

 tacilla Sylvi^lla Lhi., Curruca Sylvidlla Flem.). — Cofid. 



Vol. II. — No. 10. ii 



