ZOOLOGY, AND BOTANY MICROSCOPY, ETC. 



HO 



mg the parts. A piece of tubing is slipped over the joins of the cannula 

 and nozzle. This pressure-sheath is capable of resisting the pressure of 



Fig. 19. 



two atmospheres, and prevents the cannula 

 from becoming detached from the syringe during 

 manipulation. The illustrations show the 

 syringe (fig. 20), the two-way cock (fig. 19), 

 and the working arrangement (fig. 18). 



Vital and Supravital Granule Staining.* 

 J. Arnold has studied the grannies in epithelial, 

 endothelial and connective-tissue cells, mast- 

 zellen, leucocytes, etc. Employing the vital 

 method, he either sprinkles the tissue to be 

 examined, e.g. the mesentery, with neutral-red 

 solution, or dusts it with the same substance 

 in powder. If the supravital method is fol- 

 lowed, the tissues taken fresh from the animal 

 are placed at once in normal saline solution, con- 

 taining either *01 to - 1 p.c. neutral-red or 

 •0005 p.c. methylen-blue, as the case may be. 

 The granules appear in 10 to 20 minutes. In 

 the epithelium of the frog's bladder he finds a 

 perinuclear arrangement of granules, which he 

 thinks might easily be mistaken for karyo- 

 kinetic figures. He has compared the effects 

 of vital with those of supravital staining in 

 the case of the tongue of the frog, and finds 

 them identical. The author is of opinion that 

 cell-granules are concerned in the elaboration 

 of fat, iron and bile pigment. 



Naphthol-Blue as a Reagent for Bacterial 

 Fat.f — A. Meyer, in order to demonstrate this 

 staining reaction, uses organisms known by 

 accurate research to be rich in fat and destitute 

 of volutin, e.g. B. megatherium. He mixes a 



Fig. 20. 



* Anat. Anzeig., sxiv. (1903) pp. 1-6. 



t Centralbl. Bakt. 1" Abt. Orig., xxxiv. (1903) pp. 578-9. 



