296 SUMMARY OF CURRENT RESEARCHES RELATING TO 



result of his investigation is in the main to confirm in regard to the 

 particular case of man what has been observed elsewhere. Attention may 

 be directed, however, to Grabower's description of peculiar oval struc- 

 tures, which look like sensory end-organs and in any case do not at all 

 resemble any of the motor endings. 



Supporting-Substances of the Nervous System.* — Dr. H. Joseph 

 has reached the following chief conclusions. (1) In Annelids and in 

 many other Invertebrates, the neuroglia consists of peculiar well-defined 

 fibres, the neuroglial fibres, and shows a remarkable correspondence with 

 the neuroglia of Vertebrates. (2) In both Vertebrates and Invertebrates, 

 tbe neuroglia is a derivative of the outer germinal layer, the fibres are 

 derivatives of cells with which they probably always retain some per- 

 sistent connection. (3) Epithelial fibres and neuroglial fibres show a 

 most intimate correspondence, and are phylogenetically related. They 

 are functional structures in the clearest sense and are originally related 

 to simple requirements and functions of the cells. (4) The position of 

 the glia fibres is such that they are apposed to or imbedded in only 

 the external layer of the cell-plasm. They do not pass into the interior 

 protoplasm, as Erik Miiller supposed. 



Matrix of Vitreous Humour in the Eye of Man and Animals.j — 

 Dr. C. Addario notes that almost all investigators are agreed that the 

 Grnndsubstanz of the vitreous humour includes (a) firm fibrils forming 

 a narrow-meshed network, and (b) a fluid interfibrillar substance. He 

 has come to the conclusion that the ciliary epithelium lying directly in 

 front of the ora serrata forms and adds to the fibrillar framework of the 

 vitreous humour and must therefore be regarded as a true matrix, by the 

 activity of which a slow, but persistent growth of the vitreous humour is 

 effected. 



Skin-Pigment in Man and Monkey s.+ — Dr. B. Adachi finds in the 

 corium two kinds of connective-tissue pigment-cells, (a) small, incon- 

 spicuous elements, almost always the more external ; and (b) much larger, 

 usually deeper, very conspicuous elements. The former occur in man 

 and in all monkeys ; the latter are sometimes absent. In many monkeys 

 the large pigment-cells occur in almost every part of the body, in others 

 they are quite absent ; in man (apart from the choroid and meningial 

 membranes) they are transitory, sometimes occurring before and after 

 birth, sometimes only after birth, rarely in adult life, most abundant in 

 the lumbar, coccygeal, and gluteal regions, and especially in coloured 

 races. In many coloured races they may form blue spots on the regions 

 indicated ; in white men they are practically microscopic. They cannot 

 be regarded as racial peculiarities, nor can it be concluded that those 

 races in which they are most abundant are lower. 



" Chromatophores " — stellate pigment-figures within the epithelial 

 limits— -are often clearly seen in the normal white skin ; they are much 

 more distinct in Hylobates ; they are not cells, however, but cell-like 

 figures formed mainly by intercellular pigment-granules. A connective- 

 tissue pigment-cell, whether of the small or of the large type, never 

 reaches the epithelial boundary, either in (healthy) men or in monkeys. 



* Arb. Zool. Inst. Wien, xiii. (1902) pp. 335-400 (4 pis. and 2 figs.). 

 t Anat. Anseig., xxi. (1902) pp. 9-12. % Tom. cit., pp. 16-8. 



