CETACEA. 



It is now generally admitted that the Mystlcetus lives only on 

 small Medusae, 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 Balcena 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 Balcena 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 T ), 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 Balcena maximus there are 506 bristles 

 in the thickness of the plate, and by a rude enumeration there ap- 

 peared to be at least 130 bristles in each inch. The whole breadth 

 of the plate being 5i inches, gives us 747 bristles entering into its 

 composition. These bristles are matted together to the extent of 

 1 1 inches on the external and 5 inches on the internal margins, by 

 a substance like minute laminae or scales, and which may be seen 

 by the aid of a microscope to invest the free bristles at the fringed 

 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 Balcena maximus would not split. The re- 

 moval of the external lamina in the plate under description shows 

 the cause of this : about 6^ inches from the root of the plate, 

 many of the bristles have deviated from their direct parallel incli- 

 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 Balcena maximus 

 would be 800 to 900 years old, that being the number of trans- 

 verse lines on the longest plate of baleen. Knox, Cat. Prep. 

 Whale, 9. 



The whalebone of the smooth-bodied whales without anv back 



