116 ON SOME PROTEIN CRYSTALLOIDS. 



4- —Transfer the slide to a vessel containing absolute alcohol, 

 30 cc, and i per cent, caustic soda solution in absolute alcohol, 

 4 drops. Wait till sections are of a rust colour. 



5. — Remove all traces of caustic soda with absolute alcohol. 



6. — Rinse sections in ordinary water for one minute. Red 

 clouds are given off and the sections become bluish. 



7. — Place slides for two minutes into water slightly acidified 

 with acetic acid. This is done to deepen and fully restore the 

 blue colour and also to fix the eosin. 



8. — Dehydrate, clear with xylol, not clove oil, and mount in 

 turpentine-balsam. 



For results see Figs, i — 14. 



By using simply a | per cent, watery solution of eosin, and 

 decolourising with alcoholic caustic soda in the way detailed above, 

 I succeeded in staining the crystalloids, but the result is inferior to 

 that produced by the contrast of the double stain. Other acid 

 dyes were tried with less success, Magdala-rot (echt) giving the 

 next best results. 



I have used Mann's stain for the crystalloids in the aleurone 

 grains of the seeds of Ricimis, with beautiful results. I have also 

 examined the tissues of various plants in which Zimmermann 

 finds protein crystalloids, both with Mann's stain and with the 

 Saurefuchsin, with the result that whenever I succeeded with the 

 one method in demonstrating them, I succeeded also with the 

 other ; and whenever I failed with the one stain, I failed equally 

 with the other. 



Comparing Zimmermann's method with the one I employed, I 

 certainly prefer the latter because of the great preciseness with 

 which crystalloids are stained. 



Cytoplasmic Crystalloids of Scilla patula and Hyacinthus Sp. 



While examining the ovaries of Scilla patiila with the help of 

 the Methylblau-eosin double-stain, my attention was arrested by 

 numbers of bright red granules and crystalloid bodies in the cyto- 

 plasm of the unicellular hairs, that occur in considerable numbers 

 on the placentas in this and other species of Scilla. From their 

 resemblance to many of Zimmermann's figures, it at once occurred 



