154 NATURAL HISTORY 



those magnificent birds appear by no means to be their 

 tails ; those long feathers growing not from their uropy- 

 yium, but all up their backs. A range of short brown 

 stiff feathers, about six inches long, fixed in the vropy- 

 gium, is the real tail, and serves as the fulcrum to prop 

 the train, which is long and top-heavy, when set an 

 end. When the train is up, nothing appears of the 

 bird before but its head and neck ; but this would not 

 be the case were those long feathers fixed only in the 

 rump, as may be seen by the turkey-cock when in a 

 strutting attitude. By a strong muscular vibration 

 these birds can make the shafts of their long feathers 

 clatter like the swords of a sword dancer; they then 

 trample very quick with their feet, and run backwards 

 towards the females 1 . 



I should tell you that I have got an uncommon calcu- 

 lus cegagropila, taken out of the stomach of a fat ox ; it 

 is perfectly round, and about the size of a large Seville 

 orange ; such are, I think, usually flat. 



LETTER XXXVI. 



TO THE SAME. 

 DKAR SIR, Sept. 1771. 



THE summer through I have seen but two of that large 

 species of bat which I call Vespertilio altivolans, from 



1 In other birds, as well as in the pea-fowl, the feathers of different 

 parts sometimes assume the appearance of a tail. In the elegant Trngon 

 resplendens, which has been adopted by the United States of Central 

 America us their national emblem, the beautiful flowing feathers that 

 hang gracefully behind the bird and measure more than three times its 

 total length, although they would popularly be termed the tail, belong 

 in reality to the back. Again, in those cranes which belong to the genus 

 Anthropoiilcs, the lengthened feathers which, in the chastely elegant spe- 

 cies dedicated by Mr. Vigors to Lord Stanley, sweep like a graceful 

 train along the ground, are quite unconnected with the tail of the bird, 

 and form actually a part of the wing. E. T. B. 



