CHAPTER XIV. 



CRYSTALLOGRAPHY OF THE HEMOGLOBINS OF THE OTARIID^E, 

 PHOCID-ffi, MUSTELID^E, PROCYONID^E, AND URSID-ffi. 



Under Carnivora zoologists distinguish two suborders, (1) Carnivora 

 vera and (2) Pinnipedia. The distinction is mainly in the structure of the 

 limbs, which in the Carnivora vera are normal for terrestrial animals and in 

 the Pinnipedia are modified for aquatic progression. In the arrangement 

 of species here adopted the Pinnipedia are considered first, and then the 

 Carnivora vera, beginning with the species which, from their hemoglobin 

 crystals, appear to be most nearly related to the Pinnipedia, namely the 

 Mustelidce, Procyonidce, and Ursidce. 



The Pinnipedia are divided into the eared seals, Otariidce, including 

 the sea-lions and sea-bears, of which one species, the California sea-lion, 

 was examined ; the walruses, Trichechidce, of which we had no representa- 

 tive; and the Phocidce or earless seals, of which the harbor seal was exam- 

 ined. These are all evidently descendants of some terrestrial mammals, 

 and from the resemblances between the skulls of the eared seals and the 

 bears of the Carnivora vera, Mivart (Proc. Zool. Soc., 1885, p. 497) has 

 suggested that there exists a true genetic relationship between the two 

 groups. Mivart states that while the sea-bears may be thus related to the 

 bears, both being derived from bear-like carnivores, the true seals may on 

 the other hand be genetically related to the sea-otters. The true bears are 

 a modern group, and a common bear-like ancestor for them and for the 

 eared seals is entirely possible. It will be seen from a comparison of the 

 hemoglobin crystals of the sea-lion and of the bears that they have a certain 

 very remarkable character in common, namely, a habit of twinning that is 

 very unusual, and is identical in the two groups, but which produces differ- 

 ent-looking crystals, owing to the development of the planes of the crystals 

 being different in the two groups. This is not the only point of resemblance 

 between the two groups, as will be shown. 



The Mustelidce and Ursidce are evidently closely related, as indicated 

 by their hemoglobin crystals ; the Procyonidce, however, so far as our investi- 

 gations have gone, do not show close relationship to the other groups above 

 mentioned. Of the Mustelidce the common ferret, Mustela putorius (domes- 

 ticated variety) ; the skunk, Mephitis mephitica putida; the badger, Taxi- 

 dea americana, and the otter, Lutra canadensis, were examined. They show 

 strong resemblance to each other and to the bears and seals, with the 

 exception of the skunk, which more nearly resembles the Procyonidce from 

 what data we were able to obtain in regard to its hemoglobin crystals; 

 but in the case of this species the data were incomplete. 



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