238 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



Sections were stained with the Ehrlich-Biondi triple stain, with 

 Heidenhain's iron-haematoxylin, and those that had been treated with 

 osmic acid fixative were previously bleached with peroxide of hydrogen 

 (5-10 p.c. in 70 p.c. alcohol). 



Staining the tissue en masse was simple and satisfactory. The pieces 

 fixed in Zenker's fluid were washed in running water for 24 hours and 

 then immersed for a like time in ■ 2-0 ' 5 p.c. haematoxylin solution, 

 which contained about 50 p.c. alcohol. After frequent washing the 

 pieces were transferred to graded alcohols. For the finer details this 

 procedure was especially effective. Pieces fixed in Carnoy's fluid may 

 be treated in a similar way. They are transferred from the alcohol- 

 chloroform- acetic acid mixture to absolute alcohol and then through 

 down-graded alcohols to distilled water. The pieces are then stained in 

 the previously described iron-haematoxylin solution for 24 hours, after 

 which they are transferred to a solution consisting of 0*25 grm. potas- 

 sium monochromate and - 25 grm. potassium bichromate, dissolved in 

 100 c.cm. distilled water. 



(3) Cuttings including: Imbedding- and Microtomes. 



Reichert's New Microtome, with Double Bearings.* — The advan- 

 tage claimed for this instrument is that the bearings of the knife-carrier 



Fig. 34. 



are double and are of a trapezium shape, owing to the different lengths 

 of the four arms forming the bearings. In consequence the knife or 



* Reichert's Catalogue, French edition, 1905-6, p. 15. 



