TRANSACTIONS OF THE SECTIONS. 133 
limbs are restricted to assist the function of respiration, which is 
branchial in fishes and amphibia in their earlier life; but when the 
pulmonic system is found in air-breathing animals, the respiratory 
limb is more fully developed, for the purpose of locomotion ; and where 
both systems of respiration by lungs and gills exist, as is seen in the 
Proteus, we find both the opercular arch and the scapulo-clavicular 
arch having a limb attached, as the plates of the Axolotl, published in 
the work of the illustrious Humboldt, clearly exhibit. 
In regard to the pectoral fin, an examination of the table will show 
a more equally balanced accordance with the parts of the limb in the 
higher Vertebrals, in the analogies proposed in thiscommunication, than 
in those of Cuvier, where two bones of different laminz are called 
parts of one bone; and on the other hand, one bone is called on to 
represent two belonging to different lamin. The beautiful articular 
joint between the pelvis and femur (such as is never found with 
scapula, even when that bone exists in two pieces, as in the ribless 
frogs), first showed the key to the explanation ; and being on the inner 
aspect of the pelvis, the leg has been turned with the fibula (or coracoid 
bone of Cuvier) on the inside, and the largely developed malleolus of 
the tibia on the outside, meeting on the mesial line below the respira- 
tory organs. This change of the limb will cause the sole of the foot tu 
be placed anteriorly ; and we find that the most common action is to 
balance the animal, and enable it to back out, while the whole progres- 
sive motion in the osseous fishes is produced by the tail. The ar- 
rangement of the tarsal bones, in man, resembles very much that of the 
arm and fore-arm, and in fishes has tended to the mistaking the tarsus 
for the whole anterior extremity. 
A very opposite system was obtained in the case of the ventral fins, 
where one bone on each side support the fin-rays; these bones seem 
the analogues of the cartilages of the ribs or pubis of the Vertebrals, 
or perhaps the additional limbs on the ventral rings of the Crustacez ; 
here one bone on each side represents the two circles or lamine 
entirely. 
The author therefore considers that the anterior extremities of 
higher Vertebrals have their analogues in the opercular bones of 
osseous fishes ; and the analogue of the posterior extremities is to be 
found in the pectoral fins of the same class. 
On the Salmon Fry. By James Wison, F.R.S.E. 
The author laid before the Section a series of specimens of salmon 
fry, with a view to illustrate Mr. Shaw’s recent discoveries regard- 
ing the early condition of that important species. It was the in- 
spection of that series which first convinced Mr. W. of the accuracy 
of Mr. Shaw’s views, and he felt anxious that those who might still 
entertain any doubts upon the subject should have an opportunity of 
removing those doubts by the examination of a suite of specimens pre- 
pared by that ingenious observer. The prevailing opinion upon the 
