1896.] MICROSCOPICAL JOURNAL. 349 



terior and the Bacillariacese. It has the lower side ce- 

 mented by gum thus or balsam, though gum thus is best, 

 to an ordinary slide which is placed on the stage of the 

 microscope. The bottle is an ordinary one and can be 

 gotten easily. It is also corked, with a rubber cork, and 

 can thus have the water supplied. The small hole can 

 be bored, by using a small rat-tail file wet with spirits 

 of turpentine and one can with ease bore a hole smaller 

 or larger as wanted. I now have an excellent growing 

 slide that answers every purpose and can be employed 

 for Bacillariacese or larger objects as desired. 



Special Staining Methods in Microscopy, Relative to Ani- 

 mal Tissues and Cells. 



4. The Specific Staining of Mast-Cell Nuclei.* 



By Dr. P. G. Unna, Hamburg. Translated from the 



German by Geo. W. Cale, M. D., F. R. M. S. (London), 



St. Louis. 



It may perhaps appear unnecessary, in our series of 

 articles on staining technique, to make especial mention 

 of the mast-cells. For^ in spite of the increased interest 

 of a negative sort which these have gained since the 

 bacteriological era in our science, if one but looks to the 

 histological text-books for references, it will be seen that 

 the teachings of Ehrlich are always given as the only 

 method of demonstrating the mast-cells. The latter still 

 appears to suffice for all that could be desired as a dif- 

 ferential stain. Ehrlich, as is known, stains slowly in 

 acetic acid, or in acetic acid and glycerine, together with 

 a weakened solution of the basic dye, dahlia. While the 

 bleaching reaches all the parts of the tissues — the proto- 

 plasm, nuclei, intercellular substance — whereby the mast- 



* Mast-cells are cells filled with basophlle granules, found in the connective 

 tissue and in foci of chronic inflammation. 



