ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 263- 



Structure of Stratum Corneum in Man.* — Dr. Franz Weidenreich 

 has continued liis researches on the eleidin and pareleidin of the super- 

 ficial layers of the human epidermis, and the relation of these to the fat 

 believed to occur in the stratum corneum. Ke finds that the blackening 

 with osmic acid which occurs in the case of the skin from the palms and 

 soles, is not due to impregnation with fat from without, i.e. from the 

 sebaceous and sudorific glands, nor is the fat produced within the cells 

 from eleidin or pareleidin, but the pareleidin itself possesses the pecu- 

 liarity of reducing osmic acid, although after a much longer period of 

 action than a true fat. Neither eleidin nor pareleidin is of fatty nature, 

 but pareleidin must be included among the non-fatty substances which 

 have the power of reducing osmic acid. It is possible that in the hairy 

 parts of the skin, the blackening with osmic is due to fatty impregnation 

 by the secretion of the sebaceous glands. As to eleidin and pareleidin, 

 the author finds that the former originates from the keratohyalingranula 

 formed in the stratum granulosum. In the basal cells of the stratum 

 corneum the eleidin keeps its fluid character, but later it dries up, be- 

 comes of tenacious and colloidal consistency, and forms pareleidin. The 

 stratified appearance of the stratum corneum is due not only to this 

 transformation, but also to the existence of zones of tension and zones 

 of relaxation, w T hich affect the optical appearance. 



Histological Effects of Prolonged Fast.f — Prof. E. Yung has made 

 a long series of observations on vertebrates and invertebrates as to the 

 effect of inanition, and finds that death takes place when the body has 

 been reduced to about one-half the normal size. In Protozoa the proto- 

 plasm becomes increasingly transparent, and diminishes in amount more 

 rapidly than the nucleus, within which the chromatin becomes indistinct. 

 In fishes and Amphibians all the cells do not suffer to the same extent, 

 the intestinal epithelium being more affected than the blood-corpuscles or 

 nerve-cells. As in Protozoa, the granules of the protoplasm disappear, 

 and the nuclear chromatin is absorbed ; the general reduction of the size 

 of the body or of special organs is associated with a corresponding re- 

 duction in the size of the cells. The author believes that death results 

 from the reduction of the cells below the minimum at which their 

 functions can be carried on, this minimum varying with the different 

 kinds of cell. 



e. General. 



New Zealand Lancelet.J — Prof. Blaxland Benham has examined the 

 Amphioxus of New Zealand, hitherto regarded as identical with the 

 European form, and finds that it belongs to the genus Heteropleuron, and 

 constitutes a new species, H. hectori. The preoral hood with its; cirri is 

 unsymmetrical on its two sides, as in the larva. The two specimens ex- 

 amined were not in sufficiently good condition for much of the structure 

 to be made out. 



New Amphioxus. § — Dr. Arthur Willey describes a new Acraniate 

 from the Indian Ocean which he regards as constituting a new sub- 



* Arch. Mikr. Anat., lvii. (1901) pp. 583-622 (2 pis. and 1 fig.), 

 t Arch. Sci. Phys. et Nat., x. (1900) pp. 572-4. 

 t Quart. Journ. Micr. Sci., xliv. (1901) pp. 273-80 (1 pi.). 

 § Tom. tit, pp. 269-71 (2 figs.). 



T 2 



