1885.] Suspensory Ligament of the Fetlock in the Horse, Ox,&c. 127 
leaving for Canada. The dissection of whales is no easy 
matter. 
Here then we have these finger muscles in Megaptera not more 
developed in proportion to the size of the limb, but in a still more 
rudimentary condition. These facts, the author observed, could 
be reasonably explained only on the hypothesis of the descent of 
whales from some ancestor in which the fingers had more exten- 
sive movement. 
A’. 
Ve 
THE STRUCTURE AND DEVELOPMENT OF THE 
SUSPENSORY LIGAMENT OF THE FET- 
LOCK IN THE HORSE, OX, &c. 
BY J. D. CUNNINGHAM, M.D. 
HE author first alluded to the various examples which are 
found amongst the mammalian group of muscles becoming 
transformed into fibrous tissue and assuming the duties of liga- 
ments. He had observedemuscles thus metamorphosed in the 
foot of the pig, walrus, armadillo, elephant, &c., and Professor 
Struthers had, in a paper read before the British Association in 
Montreal, instanced a remarkable case in which a muscle in the 
rudimentary hind limb of a cetacean was completely converted 
into ligamentous tissue around its Serka whilst it remained 
muscular in its center. 
The most remarkable examples of this muscle metamorphosis- 
are to be found in the feet of the horse and ruminants. The sus- 
pensory ligament of the fetlock, as is well known, is muscular in 
its origin, and in every case its ancestry can be traced with the 
greatest clearness and precision. In the horse it is derived from 
` the fibrous transformation of the two bellies of the flexor brevis 
medii, and if transverse sections are made of the ligament, the 
remains of these bellies may be observed in its midst in the form 
of two crescentic fleshy outlines placed side by side. Every here 
and there, however, the outlines are interrupted by patches of fat 
cells and degenerating muscular fibers. The suspensory ligament 
of the ox, sheep, &c., is derived from the fusion and fibrous trans- 
formation of the four fleshy bellies of the flexor brevis annularis 
and flexor brevis medii, and in transverse section these show as 
1 Abstract of a paper read before the biological section of the American Associa- 
tion for the Advancement of Science, in Philadelphia, 1884. 
