76 

 ON THE RUMP GLAND IN BIRDS. 



BY M. REAUMUR.* 



WERE I tempted to explain why the hinder part of the hens, without 

 tails, has not a secretion performed in it like that which is observed 

 in other hens, and in other kinds of birds, in many of which I have 

 found a rump notwithstanding their want of tail; were I tempted, I 

 say, to explain it, I should be aware of the danger I should be in of 

 committing mistakes by the very obligation I think myself under of 

 exposing, as an error, the notion which the naturalists and philosophers 

 have framed to themselves Concerning the utility of the unctuous 

 liquor that issues through the one, or the two excretory canals of the 

 rump of birds. All the works of nature being lavishly rilled with 

 wondrous characteristics, fit to raise in us a most just admiration, 

 those who, from the best intentions, expose them to our eyes in order 

 to force us to acknowledge the AUTHOR of them, are, on account of 

 the multitude of those wonders, liable to some reproach, when they 

 happen to mention among them some that are not of the utmost 

 certainty. They all have been of opinion, that the feathers of birds, 

 in order to be sheltered against rain, wanted to be done over with 

 a kind of oil, or grease, that might cause the water to run off 

 them without penetrating them, and that this unction wanted to be 

 repeated from time to time : we shall prove in a memoir, that shall 

 treat on nothing but feathers, that they have been wrong to entertain 

 that notion. In consequence of it, they have pretended to make us 

 admire a reservoir of unctuous matter placed on the hinder-part of 

 each bird, out of which he expresses, and takes it with the end of his 

 bill to convey and spread it all over the feathers that want it. 



I shall not here undertake to show how little the quantity of liquor, 

 that may be daily supplied by this reservoir, is in proportion to the 

 extent of the surfaces resulting from the assemblage of the numberless 

 feathers with which a hen or a duck are covered ; nor how long a time 

 would be necessary to enable the reservoir to supply a quantity of the 

 said liquor^ sufficient to besmear the surface of only one of those 

 feathers. In order to explode a notion, that must needs have been 



* This paper is introduced from the English translation of the celebrated Reaumur's 

 woik on domestic fowls, for the benefit of those who do not read French, and who 

 publish, as their own discoveries, the well known observations of others. We shall 

 give another similar paper shortly. 



