2478 Journal of Applied Microscopy 



tion it is almost impossible to overstain ; if this occurs, acid alcohol readily 

 removes the superfluous amount. Then wash in distilled water, counterstain, 

 etc., if desired. The stain is the same, whether the material is old chromic, or 

 acid, or formalin hardened. At the most a longer time, 48 hours or so, is 

 required in these cases. Any method of embedding can be used. Celloidin is 

 good, but especially fine results come from frozen sections, stained in orcein. 

 Through evaporation of the alcohol of the stain on the section a rapid coloring 

 of the connective tissue fibers results. The author counterstained with hema- 

 toxylin, alum hematoxylin. Twenty-four hours in a weak or a shorter time in a 

 strong solution stains sufficiently. With celloidin after the latter stain, treat 

 with acid alcohol, wash in tap water till again blue. If thionin is used for con- 

 trast stain, a hot saturated aqueous solution is best. Filter as much of the latter 

 into distilled water as will make a blue mixture, too dark to distinguish the sec- 

 tions through, wash the alcohol off and stain from a few minutes to an hour. 

 This stain is only permanent if the sections are mounted in resin. A small piece 

 of the latter is melted on a slide, the section laid on a cover-slip in xylol, dried 

 with tissue paper and laid on the resin, which meanwhile has cooled sufficiently 

 to avoid injury to the section and yet remained fluid enough to use. Air bubbles 

 may be troublesome at first, but a little practice does away with them. The 

 counterstain with carbol toluidin is admirable. A concentrated alcoholic solution 

 is best. Enough of this is dropped into a 2 per cent, carbolic acid solution 

 (aqueous) to make a dark or light blue color, for rapid or slow (24 hours) stain. 

 Wash with distilled water and alcohol, differentiate in beechwood creosote if 

 necessary, clear in xylol and mount in balsam ; a permanent stain results. This 

 is especially good for mast and plasma cells ; after 24 hours staining and final 

 warming, the different micro-organisms, the pus microbes, pneumo-, staphylo-, 

 strepto-, gono-, and meningococci, as well ascoli, typhoid and influenza, are stained. 

 Owing to their dark blue color the bacteria stand out clearly from the rest of the 

 tissue. In addition to these results, Weigert's fibrin and tubercle stain can be 

 got. The tissue is stained in hematoxlyn after being well washed, sections are 

 treated with carbol fuchsin and then with Weigert's fibrin stain. a. m. c. 



Mac Cullum, W. G. On the relations of the From the study of the diaphragm of 



Lympathics to the Peritoneal Cavity in the , , , i i .^i >. ^i 



Diaphragm and the mechanism of absorp- ^OgS the author concludes that the 



tion of granular material from the Perito- peritoneal epithelium is a complete and 



neum. Anat. Anzeig. n;?-! SOi iQO'?. , , , r n -.i ^ 



^^ ^ -^ unbroken layer of cells without pre- 



formed stomata in the sense of von Recklinhausen. The cells forming this layer 

 have the power of retracting slightly from one another, the lymphatics of the part 

 form a dense layer beneath the epithelium, the radial trunks embedded in the 

 musculature and abundantly connected with the pleural network are connected 

 by arching transverse anastomose, which lie in the superficial connective tissue 

 and then come close to the peritoneal epithelium. These " lacunae " have only a 

 thin roof of peritoneal epithelium, the lymphatic endothelium and a lattice work 

 of fibrils separating them from the cavity. The endothelium, as demonstrated 

 by recognized methods, forms an unbroken membrane. Injection of the lacunae 

 with colored masses tends to prove the completeness of their walls ; they may 



