46 PROFESSOR STRUTHERS. 



some extent determine the relative length of some of the 

 phalanges. With digits near each other the nodes must lie in 

 some part of the neighbouring hollows. That the joints should 

 not be on a line with each other in the paddle is a farther 

 reason for difference in the length of the phalanges. Had they 

 been in a line with each other, transversely or obliquely, 

 the paddle would have been liable to bend or break at 

 the line.^ 



15. Muscles of the Fingers and Fore-arm. — Considering 

 the great size of the pectoral fin in Megaptera longimana, it was 

 interesting to ascertain whether finger-muscles are present, and 

 if present, whether they are more developed than in other 

 finners, or still more rudimentary.- By incisions I was allowed 

 to make in the fore-arm, when the Megaptera was on exhibition 

 at Aberdeen in February 1884, I satisfied myself that red 

 muscles were present, and I was able to dissect them fully in 

 the autumn of that year. I found the same muscles present as 

 in B. musculus, but instead of being larger, like the fingers 

 on which they act, they were not half the size of those of 



^ It may be well to mention the means taken to secure accuracy in regard to 

 these and other points in the anatomy of the paddle, besides the measurements. 

 (1) An exact paper shape was cut of the entire paddle when attached to the car- 

 case. (2) After the skin, fat, &c. , had been removed in the dissecting-room, an 

 outline of each digit was carefully traced on paper, showing the size and relations 

 of the nodes and phalanges. (3) Before the bones were macerated, saw marks 

 were placed on the proximal end of the flexor aspect of each, such as to enable 

 us to articulate every bone in its right place. 



■^ The presence of muscles in the fore-arm of a cetacean was first noticed by 

 Professor Flower, C. B. (in B .musculas, Proc. Zool. Soc. , 1865). They were described 

 in B. rostrata by Drs Carte and Macalister {Trans. Roy. Soc, 1868), and by Mr 

 J. B. Perrin {Proc. Zool. Soc, 1870). By the author, in this Journal, fully, in 

 B. musculus (1871) ; in a toothed cetacean, Hypcroodon bidens (1871 and 1873); 

 in the Greenland Right- Whale, Balccna mysticctus (1878); and in this whale, 

 Megaptera longimana, in a preliminary note, at the meeting of the American 

 Association for the Advancement of Science, at Philadelphia, in September 1884 

 {American Nuturalist, February 1885). By Dr John Anderson, in Platanista 

 gangetica {Anat. and Zool. Researches, 1878). By Sir William Turner, in 

 Sowerby's Whale, Mesoplodon hidens (this Journal, 1885), with which he gives an 

 account of his dissection of them in a foetus of B. Sibbaldii, made in 1869-70. 

 In the Narwhal, Monodon 7nonoceros; the White Whiile, Beluga; Globiccphalus 

 melas ; and in the common Porpoise, Phoccna, I found these muscles to be 

 present morphologically, but histologically represented by fibrous tissue, being 

 functionally ligaments. But in Phocena, the flexor carpi ulnaris was present in 

 the ileshy condition. {This Journal, 1871, 1877, and at the Aberdeen Meeting 

 of the British Association for the Advancement of Science, 1885.) 



