338 SUMMARY OF CURRENT RESEARCHES RELATING TO 



plasm cannot combine, either physically or chemically, with any other 

 substances, except such as are synthetically built into itself. The 

 granules and vacuoles are probably waste products. Their accumula- 

 tion round the centriole probabiy interferes with the interchange of 

 materials between centriole and periphery. J. A. T. 



Development of Heart-muscle of Pig-. — Lucille Witte {Amer. 

 Journ. Anat., 1919, 25, 333-47, 18 figs.). The early heart-tissue is 

 cellular, composed of spindle-shaped cells which afterwards anastomose 

 terminally and laterally to form a network of fibres. The striations 

 appear earlier than the discs, but only here and there throughout the 

 tissue. The discs appear in the 76 mm. stage, much earher than in 

 any other animal studied, with the exception of the cat embryo of four 

 days. The discs are at first dots or incomplete bauds beginning at the 

 periphery of the fibre and growing across. With the advance in 

 development, they become straight discs across the entire fibre, then 

 across two or more, and finally assume the more complex type of discs 

 and " risers." The discs do not appear more numerous in contracted 

 areas than in relaxed areas. The discs are not to be found at either 

 end of a series of nuclei, thus forming a cell, for they are almost 

 invariably to be found in close proximity to each other, occurring in 

 patches, and there is seldom a nucleus to be found between them. The 

 theory is put forward that the discs serve as strengthening bands in the 

 muscle fibres, since they appear at about the time of the change of the 

 cells into fibres, and increase in number and complexity with the growth 

 and activity of the heart. J. A. T. 



Haemolytic Action of Blood of Young Eels. — E. Gley {C.R. 

 Soc. Biol. Paris, ]919, 82, 817-8). The blood of elvers, still trans- 

 parent, and in process of ascending rivers, is very small in amount, 

 and it is difficult to get more than a few drops. But these sufficed to 

 show the hfemolytic action i?i vitro on the red blood corpuscles of the 

 rabbit. G. Buglia has shown (1919) that an aqueous extract of the 

 whole body is also strongly hemolytic. It may be noted also that 

 Buffa proved in 1900 that the blood of larval lampreys is as toxic as 

 that of the adults. J. A. T. 



Changes in the Teeth of the Guinea-Pig produced by Scorbutic 

 Diet.— S. S. ZiLVA and F. M.Wells {Froc. Roy. Soc, 1919, 90, Series 

 B, 505-12). The authors describe a condition of fibrosis or fibroid 

 degeneration of the teeth of guinea-pigs occurring as one of the earliest 

 changes produced by deficiency of anti-scorbutic material in the diet — 

 sometimes well marked after only ten days' feeding on scorbutic diet, 

 at a period before the animal's body weight had commenced to decline. 

 Briefly the change consists in an alteration in the fine cellular connective 

 tissue of the normal pulp to a new firm fibrosis structure devoid of cells, 

 nuclei, or any regular arrangements of constituent parts. Nerve cells, 

 blood vessels and odontoblasts all share in the process of fibrification 

 and become unrecognizable. Irregular osteoid changes in the dentine 

 occur, and the dentine presents a different refractive appearance owing 



