STrDIES OF THE MACROCHIRES. 



377 



This organ is essentially alike in Swallows and Swifts ; while, as 

 we all know, in the Trochili it is more as we find it in the Wood- 

 peckers, indexed very similar to those birds, for I find after 

 careful microscopical examination that there is no truth in a 

 statement still current that this long, slender tongue of Trochilus 

 is a double-barrelled tube to suck honey with, but these supposed 

 hollow tubes contain the prolongations of the cartilaginous parts 

 of the glosso-hyal elements of the hyoidean apparatus. 



With these few brief comparisons, which, however, are the 

 expressions of long and painstaking dissections upon the heads 

 of these several forms, I may state that, so far as this part of the 

 economy is concerned, Cypseli and Trochili are widely different 

 in all 2^ articular s, whereas Swifts show themselves to be but 

 highly modified Hirundine birds. 



Resume of some of the Points in the remainder of the 

 Axial Blceleton. 



These I will tabulate in order to bring them into as bold 

 relief as possible for direct comparison. In the Proc. Zool. Soc. 

 1885, I have already made some remarks upon the skeletons 

 of Micropus melanoleucus and Trochilus Alexandri. Here, for 

 variety's sake, we will take the Swift Chcetura pelagica and 

 Trochilus rufus\ they are essentially and respectively much 

 alike, at any rate the two first mentioned species, but I do this in 

 order to show that my first comparisons still hold good for the 

 proposed separate groups. 



Chcetura pelagica. 

 1. 12 cervical vertebra? that are with- 

 out free ribs ; 13th and 14th ver- 

 tebrae possess freely suspended ribs; 

 while from the 15tli to the 19th 

 they are true dorsals, connecting 

 with the sternum by costal ribs. 



2. The last sacral vertebra is the 29th. 



Trochilus rufus. 



1. 13 cervical vertebra; that are with- 

 out free ribs ; only the 14th vertebra 

 possesses freely suspended ribs ; while 

 the 15th, IGth, and 17th are tlie 

 only three free vertebi-a; in the dor- 

 sal region which connect with the 

 sternum by costal ribs. The 18th 

 and 19th likewise do; but I here 

 propose to consider these two latter 

 ones as leading sacrals, as they evi- 

 dently belong to that bone. This 

 gives Trochili but three true dorsal 

 vertebrcs, quite as few as any other 

 existing bird, and it is all they have. 



2. The last sacral vertebra is the 27th. 



