422 I'HXLOSOPHICAI. TRANSACTIONS. [aNNO 1740. 



was very sick by the lOth clay, and the bones of their wings were already turned 

 red. By a change of diet however, the red colour gradually decreased and 

 vanished. 



All these creatures, that had been fed with the mixture, were dissected ; 

 and the following observations made on them. Neither the feathers, the horn 

 of the bill, nor claws, had changed their colour, even where they are inserted 

 into the skin. The skin of the whole body had preserved its natural colour. 

 The brain, nerves, muscles, tendons, cartilages, epiphyses, and membranes, 

 showed nothing contrary to the usual state of these parts. But the long bony 

 tendons, that run along the great bone, which is improperly called the leg of 

 fowls, were red about the middle of their length, which is their hardest part. 

 All the true bones, even to the very thinnest of them, were as red as carmine; 

 and in some places this red was so deep, that they appeared almost black. 



In these young birds, all the bones do not take the red tinge alike. The 

 hardest are generally more coloured than those that are tenderer. A difference 

 of this kind is perceivable even in the same bone ; for the middle, which has 

 more solidity than the ends, is almost always the reddest. Not but there are 

 sometimes found little pale spots in the part where the red is deepest; and 

 sometimes spots of a very deep red in those parts which have taken but a car- 

 nation tinge. 



The great bone of the foot, which is commonly called the bone of the leg, 

 was visibly less red than the others. The little bones of the larynx and of the 

 apophyses tinged of a fine red; though these are as small as a thread in young 

 pigeons. The rings of the trachea, which are entirely cartilaginous, had not 

 taken the least tinge; but the ring nearest the division of the trachea was red 

 in these pigeons; and even the first ring of each branch of the bifurcation 

 had in several taken the tincture, in the middle at least of its outside. 



There was nothing remarkable in the thorax or the viscera; but the inner 

 membrane of the crop and intestines, especially the large ones, appeared red. 

 Having washed pieces of these crops and intestines, their outer membrane 

 continued white, and the inner, or tunica villosa, only was tinged by the 

 madder. At first sight it appeared as if injected; but on examining it with a 

 glass, it distinctly appeared, that it was not a coloured liquor that was contained 

 in vessels, as in parts injected; but that it was only a sort of faecula detained in 

 the villose part of these membranes. It is doubtless the adhesion of these 

 tinging particles of the root to the small villi of the inner membranes of the 

 organs of digestion, that is the source of all the distempers with which these 

 creatures appeared to be seized, while fed with the madder. Their crop espe- 

 cially was relaxed and flabby, as if it had been macerated several months in 



