ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 669 ' 



Carnoy's Biology of the Cell.* — In this work Prof. J. B, Carney 

 arranges his account of the structure of the cell under three heads : — 

 The protoplasm and its contents ; the cell-membrane ; and a general 

 account of the entire cell. The book on the nucleus consists of three 

 chapters, treating of the chemistry of the nucleus, its structure 

 when at rest, and its morphography. The nucleus consists, accord- 

 ing to the author, of a membrane, a protoplasmic portion (reticulum 

 and echylema) and a nuclein-filament, which contains the nuclein, 

 and forms, in typical nuclei, a continuous thread, but may break up 

 into pieces of various form, or may become absorbed and disappear 

 altogether. In his account of the structure of the nucleus, the author 

 differs in some essential points from that of Strasburger. He main- 

 tains that outside the nuclein-filament is a protoplasmic network, out 

 of which the spindle-threads are produced by division. He states 

 also that the nucleoli are sharply differentiated from the nuclein- 

 elements by containing no nuclein. The nucleohis forms a kind of 

 reserve of nuclear protoplasm, and disappears altogether when the 

 nucleus divides. The " para-nucleolus " of Strasburger is the 

 nucleolus itself. 



Decomposition of Solutions of Chlorophyll by Light. f — Dr. J. 

 Eeinke describes a series of experiments on this subject, from which 

 he derives the general conclusion that the groups of rays of the solar 

 spectrum may be arranged in the following series according to their 

 power of decomposing chlorophyll : — red, orange, violet, yellow, blue, 

 dark red, green. This series shows further that the power of any 

 given rays to decompose chlorophyll is a function of the degree of 

 their absorption in a solution of chlorophyll. The absolute maximum 

 of the curve of this power coincides with the maximum absorption 

 between the lines B and C ; from here the curve falls rapidly to the 

 ultra-red, more slowly through the orange and yellow to the green, 

 where its minimum again coincides with the minimum absorption, 

 rising then, through the blue, to a second smaller maximum in the 

 violet. The separate values obtained by observation for alcohol- 

 chlorophyll and benzol-chlorophyll nearly agree ; alcohol-chlorophyll 

 does not show any stronger decomposibility in the blue and violet 

 than benzol-chlorophyll does, which might have been expected, 

 because in the former the absorption between F and G is increased 

 by the greater proportion of xanthophyll. 



The curve of the action of the colours of the spectrum is perhaps 

 a function of the absorption in pure chlorophyll ; xanthophyll does 

 not appear to act as a sensitizer in this process. The author claims 

 if) have shown that the decomposition of chlorophyll by the rays of 

 the Run is in proportion to the absorption of the latter ; and chloro- 

 phyll no longer furnishes an exception to the general law with regard 

 to substances sensitive to light. 



• Carnr.y, J. B., ' La Biologie Cellnlairc : Ktudo oomparee do la cellule 

 HanB IcH (Icnx ihtrnce. Faae. 1. Technique microscopiquo.' 8vo, Lierre, 1884, 

 271 pp. and 141 fi^s. 



t iJot. Ztg., xliii. (1885) pp. C5-70, 81-9, 97-101, 113-7, 129-37. 



