CAPTURED NEAR BURNHAM. 127
becomes much darker after death, but in this specimen I have
observed a feature which is worth recording with regard to the
baleen ; that the delicate slate colour of the blades which I have,
became much darker after it had been cut off and become dry.
Some interesting particulars as to the great variability and sizes
of the Common Rorqual are given by Mr. Cocks in Zool., 1887,
pp. 215-18,l and 1888, pp. 205-6, also Zool. 1884, p. 456, where he
says, "The extremely thin, elongated, or seemingly-emaciated
appearance of this species is very noticeable, the posterior portion
of the back is almost sharp-edged, quite deserving the English name,
Razorback." This ill-conditioned peculiarity was very apparent in
the Burnham specimen.
One of the most interesting features in connection with this
species is undoubtedly the asymmetry in colour on the two sides of
the head, which, although unnoticed or unrecorded till of late years,
appears to be a constant character, and of specific importance.
This was first noticed by Prof. G. O. Sars of Christiana Univer-
sity in descriptions of B. musculus which appeared in "Forhand :
Videns: Selsk : Christiania," 1878, and again in 1880. In the
latter year he figures a specimen taken in Varangerfjord Finmark,
measuring about 68 ft. Engl., showing on the left side the upper
jaw and the band of the lower jaw slate-black, whilst on the right
side, about half of the upper jaw, a portion of the baleen, and the
lower jaw band and throat are white, the difference in colour being
very clear and distinct when viewed looking down upon the top of
the head.
This want of symmetry has since been noticed in several speci-
mens ;2 and in a photograph sent me (with some details) of a female
stranded at Sea View, Isle of Wight, in September, 1888, which was
no doubt of this species, though never absolutely identified, the
same difference in colour is clearly shown.
In 1884, Prof. G. A. Guldberg, Conservator of the Zootomical
Museum of the University of Christiania, writing "on the existence
of a fourth species of Balaenoptera" (borealis) (Bullet. Acad. Roy.
1 On page 215, a note by one of the whalers, Captain Sorensen, is inserted, mentioning a
kind of Rorqual called the Herling Whale (sildehval), met with during the herring fishing on
the western and southern coasts of Norway. He says it is most like the Common Rorqual, hut
is smaller, 50 to 55 feet, with the dorsal fin somewhat higher and more pointed, and yields less
oil He suggests this may he the southern form. From the description, so far as it goes, it
seems probable that the Burnham Whale belonged to this variety.
2 Notably by Prof. Pouchet in 1884, one with the right side white (Comptes rend. Acad. Sc.
Paris, Fev. 1885); by A. H. Cocks, 1884, a male at Vardo, 641/3 ft. long, the left side black and
the right side white (Zool. Ap. 1885, p. 138) : and by the same author, a male 71 ft. at Vardo,
left upper and lower lip jet black, right lips enamel or milk-white (Zool. 1889, p. 289).