1702 Journal of Applied Microscopy 



CURRENT BOTANICAL LITERATURE. 



CHARLES J. CHAMBERLAIN, University of Chicago. 



Books for Review and Separates of Papers on Botanical Subjects should be Sent to Charles J. 

 Chamberlain, University of Chicago, Chicago, 111. 



Hegler, R. Untersuchungen liber die Organ- This work has been expected ever 

 ization der Phycochromaceenzelle. Jahrb. f. gince 1895, but the poor health of the 

 wiss. Bot. 36: 229-354, pis. 5-6, 1901. ^ 



author delayed the investigation. After 



the fatal illness the manuscript, quite ready for the press, was published by Prof. 

 G. Karsten, who states that since the appearance of A. Fischer's work, the 

 author most carefully re-examined the disputed points, but without deeming it 

 necessary to change his views. The photomicrographs, with which the paper is 

 illustrated, do but scant justice to the beautiful preparations which the reviewer 

 had the privilege of examining. About forty pages are devoted to a critical re- 

 view of the literature of the subject. The rest of the paper, about eighty pages, 

 contains an account of Dr. Hegler's prolonged investigations. The principal 

 conclusions are about as follows : 



There are no naked protoplasts in the Cyanophycea;, all cells being provided 

 with cell membranes which in the heterocysts consist of cellulose and in other 

 cells consist principally of chitin. 



In the protoplast, or cell contents, may be distinguished an outer, color con- 

 taining layer and an inner colorless portion. The coloring matter is in the form 

 of extremely small granules so closely crowded as to give the impression of an 

 homogeneous color. The chlorophyll and phycocyan are contained in the same 

 granules and these granules are to be regarded as the chromatophores of the 

 Cyanophyceae. Starch or starch-like material is not present, but glycogen can be 

 identified and is the first recognizable product of assimilation. Albuminoid 

 crystals and slime vacuoles are never found in the colorless, central portion of the 

 cell. The albuminoid crystals are particularly abundant in the heterocysts and 

 spores, but are often entirely lacking in rapidly growing vegetative cells. 



Whether a nucleus is present or not is the most important morphological 

 question in connection with the Cyanophyceae and Bacteria since these are the 

 only organisms in which a nucleus has not been positively identified. The bear- 

 ing of this question upon present morphological theories of heredity is evident. 

 Since previous methods have failed to solve the problem, he devoted much atten- 

 tion to fixing and staining, and finally recommended the following : 



Saturated aqueous solution of SO 2 - - 7 parts. 



94 per cent, alcohol ----- 93 parts. 



Mix just before using and fix for twelve to twenty-four hours. Wash with 

 alcohol. 



Another fixing agent which gives good results is : 



40 per cent, formalin ----- 5 parts. 



94 per cent, alcohol 95 parts. 



