October 24, 1913] 



SCIENCE 



601 



graphic data afford a fairly eompreliensive 

 survey, for the summer months. As yet our 

 winter data are confined to Massachusetts Bay, 

 and the region just north of Cape Ann, but 

 it is proposed to continue the work at other 

 seasons in future years. The reports on the 

 ■oceanography, with preliminary accounts of 

 the plankton, are being prepared in the Mu- 

 seum of Comparative Zoology, those for the 

 summer of 1912 being now in press. And the 

 jnore important groups of pelagic organisms 

 have been distributed to specialists who have 

 undertaken the task of reporting on them. 



It would be premature to discuss the scien- 

 tific results of the cruises here. But passing 

 notice may be called to our demonstration of 

 the fact, long ago suspected by Verrill, that 

 the low surface temperatures of the north- 

 eastern part of the Gulf of Maine do not indi- 

 -cate the direct influence of an Arctic current, 

 as has so often been suggested, but are merely 

 the evidence of the strong tidal currents, 

 which cause a more or less complete vertical 

 ■mixing of the water. Where the gulf is cold- 

 est on the surface, it is warmest at the bot- 

 tom, depth for depth, and vice versa. This 

 process reaches its extreme in the Grand 

 llenan Channel, and on German Bank, where 

 the physical characters of the water are prac- 

 tically uniform from surface to bottom. 

 M[ention has already been made in the daily 

 press of our discovery of extensive beds of the 

 sea scallop (Pecten magellanicus) off the 

 coasts of New York, New Jersey and Mary- 

 land. And this promises a new fishery of such 

 importance that the Grampus was dispatched 

 southward once more, on August 20, 1913, in 

 •charge of Mr. W. W. Welsh, for a two weeks' 

 survey of the beds. 



Henry B. Bigelow 



Harvard University 



SPECIAL AMTICLES 



a:CTO-PABASITES OF THE MONKEYS, APES AND MAN 



For several years I have been urging the 

 thesis that the host distribution of the wing- 

 less, permanent eoto-parasites of birds and 

 mammals is governed more by the genetic re- 



lationships of the hosts than by their geo- 

 graphic range, or by any other ecologic condi- 

 tions. In numerous papers, and particularly 

 in a recent' one surveying all the known rec- 

 ords of the occurrence of Mallophaga on birds, 

 I have offered evidence to support this thesis. 



Now, if this contention is sound, the con- 

 verse of the statement is also true. That is, 

 the kinds (genus, species, etc.) of permanent 

 ecto-parasites found on birds and mammals 

 will indicate in some measure the genetic rela- 

 tionships of the hosts. If, for example, or- 

 nithologists have before their eyes certain birds 

 of doubtful relationships, as the hoatzins of 

 South America, or the whole family of owls, 

 they may well pay respectful attention to the 

 kinds of ecto-parasites harbored by these hosts. 

 I have, indeed, pointed out, in the paper just 

 referred to, some suggestive specific cases of 

 this sort. 



The wingless, permanent ecto-parasites of 

 birds and mammals are of two groups, namely, 

 the biting lice, Mallophaga, feeding on the 

 feathers and hair, and the sucking lice, Ano- 

 plura, feeding on blood. Certain mites 

 (Acarina) may perhaps also be assigned to 

 this category of permanent wingless parasites, 

 but the fleas can not be, for they hop on and 

 off their host, and all their immature life is 

 non-parasitic and wholly apart from their fu- 

 ture hosts. The Mallophaga, of which nearly 

 2,000 species are now known, occur chiefly on 

 birds, while the -Axioplura, of which less than 

 100 are known so far, are confined to mam- 

 mals. 



As my own study of these ecto-parasites has 

 been almost exclusively restricted to the Mallo- 

 phaga I have not been able to illustrate or 

 bolster up my thesis with niany examples de- 

 rived from conditions among the mammals, 

 but the recent careful work of Fahrenholz 

 (Hanover) and Neumann (Toulouse) on the 

 determination and distribution of certain 

 genera and species of Anoplura makes it pos- 

 sible to point out an especially interesting 

 case of host and parasitic relations which is 



1 ' ' Distribution and Species-Forming of Ecto- 

 parasites," Amer. Nat., Vol. 47, pp. 129-158, 

 March, 1913. 



