Memoir on the anatomy of the humpback whale, Megaptera Longimana / by John Struthers.

Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: Memoir on the anatomy of the humpback whale, Megaptera Longimana / by John Struthers. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    diagram i the dorsal fin is not very like this one, stands up more, and the point and both margins are different. In the small figure given by Eschricht (p. 152, fig. 48), the notch is much less marked than in this one. As seen in my figure, the anterior slope is a little concave on the basement, and becomes convex on the fin proper. No exact spot could be fixed on here for the commencement of the fin proper as distinguished from the basement, but the level of the notch behind determines that to the eye. The point is some way behind the top, with a fall of about 1 inch. The posterior border below the point is convex down to the bottom of the notch. This, with the gentle concavity of the posterior slope of the basement, renders the notch pretty sharp, more so than in the higher and more recurved fin of B. muscidus? As to situation, the distance from the cleft of the tail to the notch of the dorsal fin was 12 feet 4 inches of the 40 feet. In my 64-feet-long B. muscidus the distance was 15 feet 8 inches (height of fin 15 inches, length at base 24 to 26 inches). This would place the dorsal fin further forwards in Megaptera than in B. musculus. 7. Tail-Fin.—The form of the tail-fin is shown in fig. 3. Its greatest antero-posterior breadth was 3 feet, only 3 J inches more than the breadth of the pectoral fin ; its total width less than the length of the pectoral fin by 8 inches. The statement of the depth of the median cleft, commonly said to be deep, will depend on where the measurement is taken. From between the neighbouring convexities, about 7 inches out, the depth is 3 J inches; from between the first prominent serrations, about 1 Abhand. Jconig. Acad, der Wissenschaften, Berlin, 1829, Taf. v. fig. ]. ^ I have noted these points particularly on account of the question of the origin of the name Humpback for this species. Les megapteres ont une bosse sur le dos i la place d'une nageoire—une veritable bosse dependante de la peau, says the eminent cetologist P. J. van Beneden. There was nothing in the appearance of the back of this Megaptera to suggest to us the appropriateness of the name Humpback. That, however, wUl depend partly on the idea one associates with the word humpbacked. The name may have arisen rather from the rounded back Megaptera shows above water, as long ago suggested and figured by Eschricht {Untersuchungcn uber die Nordischen TValUhiere, p. 152, fig. 48) :—Der Name EumpbacJc scheint iibrigens nicht nur von der Riicken- flosse, sondern eben so wohl von dieser Kriimmung des Riickens beim Unter- tauchen. The term, though rather misleading as to the true form, is a co}i- venient one to the whale-fishers.