STUDIES OE THE MACEOCHIBES . 
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, indeed 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 particulars , whereas Swifts show themselves to be but 
highly modified Hirundine birds. 
Resume of some of the Points in the remainder of the 
Axial Skeleton. 
These T will tabulate in order to bring them iuto 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 Ghcetura 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. 
Ghcetura pelagica. 
1. 12 cervical vertebrae that are with- 
out free ribs ; 13th and 14th ver- 
tebras possess freely suspended ribs ; 
while from the 15th 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 vertebrae that are with- 
out free ribs ; only the 14th vertebra 
possesses freely suspended ribs ; while 
the 15th, 16th, and 17th are the 
only three free vertebrae 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 
vertebrce, quite as few as any other 
existing bird, and it is all they have. 
2. The last sacral vertebra is the 27th. 
