REVIEWS AND BOOK: NOTICES. 633 
though it has been generally recognized as only a single bone. 
Prof. Morse’s figures show plainly that there are always two 
ossific centres, and that the ossicles are often as distinct from 
each other as are the metacarpals they respectively cap. This 
important point may be considered as established. The author is 
uncertain of the homologies of these two far bones, querying whether 
that one capping the mid-metacarpal be intermedium and centrale 
connate, or carpale iii (“ magnum ”) ; but he provisionally holds 
it as carpale iii, and the other as carpale iv, as marked in all his 
figures. 
The sentence we have italicized above will be met with surprise 
if not with suspicion, and we cannot believe, upon the data fur- 
nished, that more than four carpals occur. Indeed, the author 
himself explicitly records his uncertainty respecting the “ extra” 
carpals mentioned as apparently present in Tyrannus and Den- 
dræca. The piece marked “c” in figure 47 (Tyrannus) is doubt- 
less “ the result of accidental pressure” which separated it from 
carpale iii, while that marked “2” in figure 48 (same bird) seems 
unquestionably pressed apart from radiale; in each case we would 
emphasize the author’s words: ‘‘it is safe to reject its occurrence 
for the present.” In the case of Dendreeca, we think that the diffi- 
culty of the supposed extra carpal can be satisfactorily explained. 
Prof. Morse has been led to believe that “ the ulnare may unite 
with the ulna,” because he several times observed a close mutual 
_ appression of the two bones, and failed to find an ulnare at all in 
two instances. But in figure 43, where no ulnare is represented, 
we are satisfied that the missing bone simply escaped the field of 
the microscope; while in figure 44, the bone marked “i” and 
Supposed to be an additional carpal on the radial side is, in our 
judgment, the ulnare itself accidentally displaced to the right. In 
this last figure, it will be observed, the author queries the ulnare 
as having anchylosed with the ulna; but unless we are altogether 
misinformed, no such anchylosis ever occurs. In all birds, so far 
as we know, the ulnare persists free, and gives an insertion to the 
Jlexor metacarpi ulnaris (just as is incidentally shown in fig. 34). 
Accounting as above for the respective disagreements of figures 
43, 44, 47 and 48 with the others, all the figures show clearly the 
four carpal bones that the author may justly claim to have 
established. 
Respecting the carpal-tarsal homologies, of which the author 
