Jeffries on the Fingers of Birds. 7 
but natural to compare it part for part with the limbs of these 
animals. § 
If we take an adult bird we find two ossicles at the distal end 
of the forearm ; these are called the ulnorcarpal and radio-carpal 
bones. Next we have a compound bone made up of shafts, rep- 
resenting as many metacarpals. These in turn are capped by 
finger points, of the formulas i, 2, 1, (e. g., Passer es ) , 2, 3, 1 
(e. g., Ducks), or 2, 2, .1 (e. g., Coot). 
The two carpel bones have, as a rule, been simply referred to 
the first row ; while thosev of the second were considered to be 
anchylos with the metacarpals. Whether the metacarpals are 
the I— III or the II-IV has been a mooted question, Rolleston, 
Huxley, and Gegenbaur holding the first view and Owen, Wy- 
man, Morse, and Coues holding the second view. 
The first study of the development of the carpus was made by 
Gegenbaur, who showed that the carpals were joined to the 
metacarpals, and that the three metacarpals were at first separate. 
Next Dr. Morse studied the carpus and tarsus of small birds in 
their normal condition. By this means he demonstrated the ex- 
istence in the embryo of the radiale, ulnare, and 2d, 3d, and 4th 
carpals of his determination, also in some cases the intermedium 
( Dendroeca cestiva ), and the centrale ( Tyrannus carolinensis) . 
About the same time Rosenberg studied the carpus of the chick 
in a systematic way, longitudinal and transverse sections being 
made of the wing in various stages of development. The result 
is that he has shown that the carpus is represented by the radiale, 
intermedio-ulnare, and two carpal bones supposed to be the ist- 
2nd and 3rd~4th. Also that the metacarpus is represented by 
four long bones, the fourth one being on the ulnal side. These 
he considers to be the first four.* 
Very good sections can be obtained by soaking the wing in a 
2 %"5% solution of chromic acid and then in alcohol of increasing 
density till 95 % is reached. The wing thus treated should be 
imbedded in paraffine or some similar substance, then cut in the 
thinnest possible sections and mounted in balsam or a glycerine 
compound. It is not necessary to stain the object, though this is 
an advantage. A wing can be made perfectly transparent for 
*-I, however, find what seems to be a discrete 1st carpal in the Redstart; Morse has 
done the same of other birds. 
