Dr. E. Crisp on the Anatomy o/Trochilus colubris. 71 



The brain weighed 3 grains, forming a large proportional amount to 

 the body (-^) ; the alimentary canal measured 3^ inches. 



The crop membranous and capacious ; the gizzard moderately 

 thick, with a soft cuticular lining. A small elevated spot was ob- 

 served (under the microscope) on the surface of the rectum, which 

 probably was the rudimentary appendix. 



The trachea consisted of about sixty rings, and the left bronchus 

 of forty — the latter being nearly the length of the trachea. The 

 ovary very small. The os hyoides long and very muscular, extend- 

 ing, as before stated, to the space between the orbits. The tongue 

 from the base of the os hyoides fourteen lines in length, the bifid 

 portion being eight lines. This latter part appeared to be composed 

 of two elastic cylinders having a membranous web on their inner 

 sides ; these webs towards their extremities, as seen in the drawing, 

 present a shreddy, torn appearance, the torn portions being of a 

 triangular shape, their bases towards the cylinders. These cylinders 

 were not hollow, but composed of a solid cartilaginous material. 

 The eyes measured two lines in diameter, and weighed about one 

 grain. 



Skeleton. — The enormous depth of the sternum in this little bird 

 at once excites attention. The sternum is of a triangular shape, its 

 anterior and deepest portion measuring four lines, its length 6| lines: 

 the cervical vertebrae twelve, the coccygeal five, ribs seven ; flat, broad, 

 and thin. The depth of the sternum and the great proportional size 

 of the pectoral muscles probably exceed those of any other bird, 

 judging from the sterna of several hundred species of birds that I 

 have inspected. The humerus very short, one line ; carpus two lines ; 

 metacarpus two lines ; phalanges 3i lines ; femur two lines ; tibia four 

 lines ; tarsus 1 ^ line ; longest toe three lines ; the claws curved and 

 sharp. The bones of this bird did not contain air. 



Remarks. — I have been somewhat minute in the description of 

 the measurements of the skeleton, because it is only by comparison 

 with the skeletons of other birds that any practical and useful results 

 can be arrived at. The shortness of the humerus is one remarkable 

 feature ; and in this respect there is a great resemblance to the same 

 bone in the Swifts (Cr/pselince). It is curious that this bone in our com- 

 mon Swift {Cypselus apus), although of very small size, contains air. 

 By some it will be thought singular that the very swift-flying bird 

 the Humming-bird should have no air in its bones ; but when we 

 consider, as I have stated in ray papers upon this subject in our 

 ' Proceedings' (1857, pp. 9 and 215), that the bones of two of our 

 swiftest-flying birds — the Swallow and Martin — contain no air, the 

 absence of it in the bones of this bird will appear less remarkable. 

 In the first paper alluded to (p. 12), I have stated that Professor 

 Owen, in his * Lectures on Comparative Anatomy,' vol. ii. p. 34, 

 remarks that the Swifts and Humming-birds are said " to have air 

 in every bone of the skeleton, down to the phalanges of the claws." 



I repeat this because several physiologists and lecturers on com- 

 parative anatomy still adhere to the old doctrine of the presence of 

 air iu the bones of all birds ; and on asking a celebrated physiolo- 



