83 
ZOOLOGICAL SECTION. 
Thursday, November 8th. — Dr. Henry Fripp, President of the 
section, in the chair. 
Mr. S. H. Swayne read a paper on " Baleen, or Whalebone." He 
said that this curious animal substance is derived from the Edentalous 
division of the Cetacea, which comprises the genera Balcena, Balcenoptera 
and Megaptera. The " right," or whalebone whales have no fin on the 
back, a very bulky body, and an enormous head, with very long straight 
baleen plates. The Balcenoptera, or " Fin-Whales," a slighter form and 
smaller head, a high fin on the back near the tail, a plaited belly and 
twisted baleen plates. The Megaptera, or " Humpbacks," a blunt-shaped 
head, a lump or excrescence instead of the back-fin, and baleen like that 
of Balcenoptera. At least three principal forms of Right-whale are known, 
represented by the Greenland, the Cape, and the North Atlantic. Of 
these there are probably several species. The two former furnish most of 
the baleen of commerce. The head is largest in the Greenland (Balcena 
Mystieetus) being one-third the total length and thick in proportion. This 
depends chiefly on the size and length of the jaws. The wide space 
between the narrow highly-arched upper jaw and the straighter lower jaw 
is occupied externally by the baleen plates, covered by the very large lower 
lip. The plates form two series of upwards of 300 on each side, and with 
two corresponding series of short subsidiary plates inside them, combine 
to make a large vaulted roof to the mouth. The shape of each lamina or 
plate is a long triangle, of which the base is broadest in the Fin-Whales 
and Humpbacks, and is attached edgewise to the sloping sides of the 
narrow upper jaw; the apex pointing downwards and outwards towards 
the widely- spread branches of the lower jaw, one smooth edge looking 
outwards and a little backwards, and the other fringed throughout with 
bristles several inches long, being turned inwards towards the large tongue. 
The whole roof of the mouth is thus covered with a bristly lining, which 
serves to entangle the small Pteropods, &c, upon which the whale subsists. 
When feeding, the whale takes in a mouthful of water, full of these floating 
Molluscs, and on closing the mouth the water escapes again laterally 
between the baleen-plates. For the most part the plates are pretty uniform 
in length, but they rather suddenly diminish at each end of the series, 
from perhaps 1 1 or more feet in the middle to three or four inches at the 
ends. The bases of the plates are embedded in a soft white spongy gum, 
which also forms a raised bead or edge along the outside of each series, 
and is called the <f wreath-band." Dr. Gray has described several varieties 
of baleen, which he thinks may belong to as many species of Right-whale. 
Of these the Greenland is the best, being long, flat, and tapering. The 
baleen of Balcenoptera and Megaptera is short, from a few inches to about 
two and a half feet long, and broad in proportion, with coarser bristles, 
and is commonly curved or twisted. A thin section of baleen exhibits in 
