﻿BRIEFER ARTICLES 



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In the Hull Botanical Laboratory, after a long series of rigid com- 

 parative tests of the various paraffin solvents in general use, it was found 

 that xylol when carefully used gave uniformly better results than any 

 other solvent. Cedar oil was rejected because it is almost if not quite 

 impossible to eliminate the oil in the final stages of imbedding. It is 

 true that hard material cuts somewhat better after cedar oil, but the same 

 end may be attained in a far better way by soaking the imbedded 

 material in water. 



Chloroform was abandoned because in transferring from alcohol to 

 chloroform it was found that, even when a much closer series than the 

 one recommended by Professor Mottier is used, some plasmolysis 

 results. Also we have found that paraffin does not seem to penetrate the 

 tissues as readily after chloroform as after xylol. These results should 

 be expected when we remember that the specific density of chloroform 

 is nearly twice that of either alcohol, xylol, or paraffin. In Stras- 

 burger's laboratory chloroform was practically abandoned for xylol 

 about 15 years ago. We have in this laboratory preparations of root 

 tips as well as of Liliutn anthers showing reduction division, which, from 

 the maker's name, we assume were made exactly as described by Pro- 

 fessor Mottier. These preparations are certainly inferior to those in 

 which xylol was used as a solvent. Dr. L. W. Sharp, one of the most 

 successful workers in the peculiarly difficult field of modern cytological 

 technique, always uses xylol as a solvent. 



If all stages in cytological technique received equal care, published 

 results would undoubtedly be in closer accord than they are at present.— 

 W. J. G. Land, University of Chicago. 



BESSEYOSPHAERA, A NEW GENUS OF THE VOLVOCACEAE 

 Two new species of the Volvocaceae were described by Powers 3 

 without names or assignments to taxonomic positions. They were 

 designated "first form of Volvox" and "second form of Volvox." The 

 former was subsequently further described and named Volvox spcr- 

 matosphaera. 1 The "second form" is intermediate between Pleodorina 

 and Volvox in the scale of differentiation, and its assignment to either 

 genus would involve so great an extension of the conception of the 



