THE 
VETERINARIAN. 
VOL. LIII. 
No. 634. 
OCTOBER, 1880. 
Fourth Series, 
No. 310. 
Communications and Cases, 
POLYDACTYLISM IN THE CAT. 
By T. Spencer Cobbold, M.D., F.R.S., Professor in the 
Royal Veterinary College. 
TwENTY-sixyears back, when occupying the postof Curator 
of the Edinburgh University Anatomical Museum, I pub¬ 
lished in the Edinburgh New Philosophical Journal some 
remarks illustrative of an apparent law of deterioration 
affecting the axial skeleton of fishes, the paper being chiefly 
based on facts observed in the dissection of a remarkably 
deformed trout captured in the river Jed, near Jedburgh. 
The slight development of the appendicular skeleton in 
fishes renders the study of malformations of their extremities 
less striking than obtains in the case of the higher verte¬ 
brates. To be sure, as references given in the paper alluded 
to were designed to show, distorted and otherwise malformed 
fins are extremely common in the salmon and trout family, 
and we all know how readily such abnormal characters are 
propagated in goldfishes reared for ornamental purposes. 
Teratology has generally been regarded as an unprofit¬ 
able study, at least, it was conspicuously so considered until 
the publication of Mr. Darwin's well-known work, in which 
he demonstrated its value and significance in relation to 
questions of heredity. The facts I now place on record will, 
Lin. 46 
