DOUBLE STAINING NUCLEATED BLOOD-CORPUSCLES. 295 



soluble substance, and entirely replaced the eosin, which was a 

 saturated watery solution. The whole of the corpuscles were 

 stained a deep orange. So far I have been able to do little 

 with aurin as a dye^ its great insolubility causes every solution 

 speedily to deposit crystals. 



E.ed and yellow. (Fuchsin and anilin primrose.) 

 Fuchsin, a salt of rosanilin, is a fine lake dye^ partly soluble 

 in water, freely soluble in dilute spirit. Anilin primrose, a 

 penetrating yellow dye of the colour of picric acid, almost in- 

 soluble in watQr, and only partly in methylated spirit, from 

 which it quickly deposits crystals. After some difficulty in 

 obtaining a good specimen the corpuscles were found to have 

 stained thus. The nucleus, a yellowish red, not unmixed 

 crimson, the remainder of the coloured corpuscles a light 

 yellow, and the colourless corpuscles a light red. The com- 

 bination was not a good one, as the yellow proved a very diffi- 

 cult dye to turn out, but, judging by results, it had the greater 

 affinity for the protoplasm of the corpuscles, and less for the 

 nucleus. 



Red and green. (Rosein and iodine green.) 

 Rosein, similar to fuchsin, but of a more deep crimson, is 

 partly soluble in water, very soluble in dilute spirit. Iodine 

 green is freely soluble in water ; an excellent combination. 

 The coloured corpuscles were stained a bright red, with bluish- 

 green nuclei. The colourless corpuscles were easily made out 

 to be of three varieties in the blood (of newt) : 1, entirely 

 stained in green ; 2, partly stained in green and partly yellowish 

 red, the nucleus green, and the surrounding protoplasm of the 

 other colour ; 3, the large masses of nuclei-like bodies, said to 

 be developing colourless corpuscles, were deeply stained in 

 green. 



The relation in size of the nuclei of the colourless corpuscles 

 to the stroma is a very variable one. Sometimes the nucleus 

 appears to occupy nearly the whole cell, at others, perhaps, not 

 more than a fourth or fifth of it. It would be possible to de- 

 scribe a larger number of different kinds of colourless cor- 

 puscles than the above if their reaction to the dyes were alone 



