62 StTMMARY OF CURRENT RESEARCHES RELATING TO 



brain and end on its outer surface. The apical end-surface usually 

 shows cilia with basal corpuscles and some hint of secretory activity. 

 The author has found in trout and goldfish a second kind of cell, which 

 he calls " neuro-ependym-cells." Their peripheral end branches in den- 

 dritic fashion, recalling ganglion-cells. There are transitions between 

 these and the ordinary ependym-cells. 



Structure of Arterial Wall.* — R. Bonnet describes the three 

 layers of the arterial wall. 1. There is the endothelial lining with 

 intricate functions in the exchange of material and in preventing coagu- 

 lation. 2. There is the accessoria (sub-endothelial or striated layer 

 + elastica interna + musculo-elastica + elastica externa) which has to 

 do with the flow of blood, and changes markedly with age and function. 

 3. There is the conjunctiva (externa or adventitia), a combination of 

 ordinary and yellow connective-tissue, with various dispositions of fibres. 



Chromatophores of Teleosts.j — E. Ballowitz has studied the chro- 

 matophores in the dermis, distinguishable according to their contents as 

 melanophores, xanthophores, erythrophores, and guanophores (or irido- 

 cytes). Hitherto these have l3een described as isolated single cells, 

 except that Heincke and Pouchet have noted the occurrence of a dark 

 chromatophore in the middle of an iridocyte (Heincke) or in the middle 

 of a mass of guanin spangles. 



In Trachinus and other types, Ballowitz has found a peculiar combina- 

 tion of dark and otherwise pigmented chromatophores and guanin-con- 

 taining iridocytes. Numerous iridocytes lie closely together in roundish 

 or irregular clumps, and encapsuled within this is a space occupied by a 

 large melansphore with two or more nuclei. Spoke-like processes of the 

 melanophore extend out between the elements of the capsule. The 

 pigment flows in these processes and the channels must be complicated, 

 for the pigment may appear even on the outside of the iridocytes. The 

 observer calls this composite chromatophore a melaniridosome. The 

 appearance varies greatly according to the expansion of the pigment, 

 which modifies the iridescence of the iridocytes. 



c. General. 



Effect of Nutrition on Hepatic Cells.J — W. Berg has shown that 

 in salamanders which have been well fed with grape-sugar and the like, 

 the liver-cells show an accumulation of homogeneous globules of stored 

 proteid. These undergo vacuolization and disappear when the animals 

 are starved. The same globules are to be seen in the liver-cells of other 

 Amphibians and in Mammals. 



Action of Rontgen Rays on Ovary.§ — Manfred Fraenkel has shown 

 that Rontgen rays bring about definite changes in the ovary. They 



♦ Ver. Anat. Ges. in Anat. Anzeig.,xli. (1912) Erganz. pp. 7-11 (2 figs.). 



t Anat. Anzeig., xlii. (1912) pp. 186-90 (2 pis.). 



X Anat. Anzeig., xlii. (1912) pp. 251-62 (11 figs.). 



§ Arch. Mikr. Anat., Ixxx. (1912) Abt. 2, pp. 61-77 (1 pL). 



