150 The Microscope. 



We are glad to notice that Dr. Alfred C. Stokes' admirable 

 paper, " Observations on Chfetonotus," which appeared in The Micro- 

 scope for January and Febmary is receiving the attention it de- 

 serves, both in this country and abroad. Many short notices of the 

 article have appeared in foreign scientific publications, and Dr. Pelle- 

 tan has published a translation of the entire paper for January and 

 February, including the plates, in his Journal de Micrographie. 



AcKNowLEGEMENTs. — W. H. Curtis, HaverhiU, Mass., fine slides 

 of diatoms on alg?e ; from Prof, S. H. Gage. Cornell University, 

 slide of areolar tissue from cat's arm ; from Dr. Thomas Taylor. 

 Washington, slides of butter and fat crystals, photographs and 

 engravings of fat crystals ; from Parke, Davis & Co., an admirable 

 portrait of Dr. Robert Koch, of Berlin, the discoverer of the tubercle 

 and the comma bacillus. A copy of this picture will be sent to all 

 professional readers of The Microscope upon application. 



Captain F. C. Gnigan, of Fort Barrancas, Fla., has our 

 thanks for courtesies received. 



TECHNOLOGY 



Preparing Sections of Stem and Root. — In his investigation 

 of the origin of lateral roots in Dicotyledons, (Ann. Sci. Nat. 

 Pt. III., 188G), M. A. Lemaire found that sections simply hard- 

 ened in alcohol were not available, owing to the contraction of the 

 protoplasm : The same objection applies to the use of calcium 

 chloride, the presence of tannin is also a serious obstacle to their 

 examination. M. Lemaire finds that the following process produces 

 good results. The section is first placed in the solution of sodium 

 hypochloride known as Eau de Labaraque, until the coloring matters 

 are destroyed and the nu.cleus and protoplasm dissolved, the cell- 

 walls being left intact. This requires a submersion of from 15 to 

 20 minutes, but one to two hours produces no bad effect. The best 

 staining material is thin anilin-brown, which he uses as a solution of 

 f per cent, in absolute alcohol, then place in oil of cloves until 

 they attain the desired transparency, and finally mount in Canada 

 balsam. Sections prepared in this way are remarkably clear, and 

 may be preserved for a long time. Mounting in glycerin does not 

 answer so well. The process will apply to the study of all meris- 

 matic tissues. — Journal R. M. Society. 



