8 CETACEA. 
It is now generally admitted that the Mysticetus lives only on 
small Medusz, shrimps, &c., but that the other species of Whale- — 
bone Whale devour inconceivable quantities of fish ; for instance, — 
M. Desmoulins states that ‘600 great cod and an immensity — 
(probably as many thousand) of pilchards have been found in © 
the stomach of a single Rorqual.”’ 
Mr. F. Knox, in dissecting the Balena maximus, saw no cavity — 
in the course of the viscera which could have contained six cod — 
of ordinary size; that of B. minimus was empty, although the 
Firth of, Forth, particularly at and above Queensferry, abounds at — 
all seasons with herrings and other fishes and their fry. The want — 
of teeth by no means renders it impossible that the Balena with — 
baleen can live on large fishes ; but the extreme narrowness of the 
gullet (that of B. maximus barely allowed the passage of the closed — 
human hand, and that of B. minimus was certainly narrower than 
that of an ordinary-sized cow), added to the want of teeth and 
the want of proper authenticated information on the subject, are 
strong arguments in favour of the hypothesis that they do not.— 
Knox, Cat. Prep. Whale, 16. 
The thickness of the plate of baleen depends on the number of — 
bristles. In the baleen of Balena maximus there are 506 bristles 
in the thickness of the plate, and by arude enumeration there ap- 
peared to be at least 130 bristles in each inch. The whole breadth 
of the plate being 53 inches, gives us 747 bristles entering into its 
composition. These bristles are matted together to the extent of 
11 inches on the external and 5 inches on the internal margins, by 
a substance like minute lamine or scales, and which may be seen 
by the aid of a microscope to invest the free bristles at the frmged 
extremity of the plate. We have often observed the facility with 
which some baleen can be split up, and were struck with the fact 
that the baleen of Balena maximus would not split. The re- 
moval of the external lamina in the plate under description shows _ 
the cause of this: about 63 inches from the root of the plate, 
many of the bristles have deviated from their direct parallel mehi- — 
nation, and become intimately twisted and interwoven with each — 
other. It has been attempted to prove the age of the Whale 
from an examination of the baleen, in the same manner as we 
judge of the age of cattle by certain annulated markings on the 
horns. On the plate before us we can distinctly perceive nume- 
rous transverse lines crossing the course of the bristles at right 
angles. If these transverse lines indicate a periodical check to 
the growth of the baleen, then the age of the Balena maximus 
would be 800 to 900 years old, that being the number of trans- 
verse lines on the longest plate of baleenKnoz, Cat. Prep. 
Whale, 9. +t 
The whalebone of the smooth-bodied whales without any back — 
ti eT 
