660 SUMMARY OF CURRENT RESEARCHES RELATING TO 



prominent ; and it is suggested that different plasmic appearances may- 

 represent different phases of function. It is enough to say that the 

 value of the work has been enhanced. 



c. General. 



Fauna of Japan.* — Dr. Arnold Jacobi has a brief note upon the 

 Vertebrates of Japan, their distribution and origin. He believes that 

 the problem of the Japanese fauna has been needlessly complicated by 

 the inclusion in the area of the Kurile Islands on the north, and the 

 Lutschu and Bonin Islands on the south. When these are excluded, it 

 is seen that Japan affords an example of a mixed region, its fauna con- 

 sisting of three distinct elements, an endemic fauna due to the insular 

 separation, and continental forms introduced at various periods from 

 north and south respectively. Part of the peculiarities may be ascribed 

 to the great meridional extension of the island chain, part to the variety 

 of climatic conditions within a narrow area. 



Vibrissa on Forepaws of Mammals.f — Mr. F. E. Beddard notes 

 that there have been incidental references to the occurrence of an inner- 

 vated tuft of hairs on the wrist, as Bland Sutton noted for Lemurs. 

 Beddard has found such vibrissas on those Lemuroids, Carnivores, 

 Eodents, and Marsupials that use their forepaws as climbing or grasping 

 organs, or in both ways. They may be really detected by touch, and 

 they are often conspicuous in colour. Thus in a pale almost albino 

 example of the squirrel Sciurus maximus, the hairs were black, and in 

 a black cat they were white. 



Phylogeny of Mammalian Hairs.}— Prof. A. Brandt discusses four 

 hypotheses : — (a) that hairs are derivable from reptilian horny scales ; 

 (b) that hairs are comparable to epidermic proliferations which occur 

 here and there in cold-blooded animals, e.g. to the Perlausschlag of 

 Cyprinoids ; (c) that hairs are modifications of the sensory papillae of 

 Amphibians ; and (d) that hairs are in structure and development related 

 to teeth, and derivable from placoid Selachian scales. It is the fourth 

 hypothesis which commends itself to the author. He discusses the 

 structural correspondence, the similarity in mode of development, and 

 possible transitional structures such as the bristle-like outgrowths on 

 Selache maxima. 



Function of Thyroid. § — Herr Oswald has been led to conclude 

 that the bearer of the specifically potent substance of the thyroid is the 

 iodine-containing thyreoglobulin, and that the colloid of the normal 

 gland is a mixture of this thyreoglobulin with a nucleoproteid. 



Carotid Gland and Suprarenal Capsule in Mammals. ||— Dr. Swale 

 Vincent discusses the bearing of recent work on his view that the carotid 

 gland is the equivalent of the medulla of the suprarenal in mammals, 

 and of the suprarenals of Elasmobranchs. He considers that Kohn's f 

 results support this view, and that the differences between his own work 



* Zool. Jahrb. (Abt. Syst. - ), xiii. .(1900) 'pp. 403-78 (1 map). 

 t Nature, lxii. (1900) p. 523. J Biol. Oentralbl., xx. (1900) pp. 572-92. 



§ Munchener Med. Woehenschr., No. 33, 1899. See Beihefte Bot. Oentralbl., is. 

 (1900) pp. 382-5. || Anat. Anzeig , xviii. (1900) pp. 69-76. 



^f Cf. this Journal, ante, p. 5G0. 



