206 THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 
As the sternum is to be regarded partially in the light of a rudimentary organ, 
it is not surprising that it varies widely, like all other rudimentary parts. In 
adults, however, the variation appears to be less than in other species of Balenop- 
tera. Little stress can be laid upon the form of the sternum of the Massachusetts 
specimen from a systematic point of view, as there are no other American specimens 
with which to compare it, and it is not from an adult. 
The scale of Eschricht’s figures, copied above, appears to have been incorrectly 
given by him. : 
As I remarked at the beginning of this chapter, the American material at 
command is so meagre as to be unsatisfactory for the solution of the questions 
at issue. Nevertheless, I think the remarkable correspondence between the careful 
measurements of Sir Wm. Turner on the Scotch skulls, and my measurements of 
the skull from the coast of Massachusetts, is a sufficient proof of the identity of the 
latter specimen with B. acuto-rostrata. It is my opinion that the lack of corre- 
spondence in other particulars between the American specimens and those from 
European waters is due partly to accuracies in descriptions, measurements, and 
drawings, and partly to age and individual variation. 
Regarding the identity of Greenland specimens with those from the United 
States, I am unable to offer any new proof, not having had any material from the 
former locality. The opinions of those who have compared Greenland and Euro- 
pean specimens in the various European museums are cited below. 
OPINIONS OF EUROPEAN CETOLOGISTS REGARDING EUROPEAN AND AMERICAN SPECI- 
MENS OF B. ACUTO-ROSTRATA. 
Lacépéde (1803-4) treats Fabricius’s Greenland B. rostrata and Hunter’s North 
Sea specimen as one and the same species, but without critical remarks. It was 
not long afterward that the species itself all but dropped from view on account of 
Cuvier’s destructive criticism of the species of Finback whales. 
In 1840 and the years immediately succeeding, Eschricht received three skele- 
tons of immature females of the small whalebone whale of Greenland (the first of 
their kind to arrive in Europe), and as he already had a skeleton of a Vaagehval 
from the coast of Norway, he was in a position to institute comparisons of value. 
He appears at first to have regarded the Greenland species as distinct, but in his 
Untersuchungen (1849) he withdraws this opinion in favor of the view that it is 
the same as the European acuto-rostrata, specifically if not subspecifically. He 
remarks: “In consequence of the new light on the subject, I must, at all events, 
confine myself to the view that the Greenland and Norwegian dwarf-whales appear 
to show the same subordinate mutual variations which are found in many species 
of land-animals in their varied geographical distribution ” (p. 174). 
This remark leads the way to considerations of the most fundamental im- 
portance from a taxonomic point of view. Many such minor geographical varia- 
tions as those alluded to by Eschricht are at this day commonly recognized as 
species and subspecies. That they exist among whales as among land animals is 
