120 



Dr. W. Stirling and A. Eannie. 



partially divided nuclei were frequently to be seen m the coloured 

 blood-corpuscles of the frog. 



Tartaric Acid. 



On irrigation with a 12 per cent, solution of this acid, the first 

 effect observed was an unequal shrinking of the corpuscles, so as to 

 produce a very peculiar effect. Each corpuscle appeared with a series 

 of bars across it, so as to present a series of alternate dark and light 

 coloured areas. These areas not unfrequently resemble a series of 

 folds or creases in the corpuscles. Sometimes these areas were 

 arranged with considerable regularity across the corpuscle, whilst at 

 othe'r times they were irregular, and sometimes radiated outwards. 

 The lighter areas seemed to be produced by the corpuscle becoming 

 thinner at these parts, as if it were the result of osmosis taking place 

 unequally and irregularly. This effect, however, soon gives place to 

 another, wherein the corpuscles suddenly swell up and burst. Go- 

 incident with this swelling up, there is a great commotion in the 

 material elements of the corpuscles, the nucleus is not unfrequently 

 liberated, and can be seen to pass out of the disintegrated hull of 

 the corpuscle, becoming at the same time completely decolorised. 

 Immediately before bursting, the barred arrangement of the haemo- 

 globin just described disappears, and the nucleus, which until then 

 had been pale and indistinct, becomes more distinct, yellowish in 

 colour, and more granular in appearance. The swelling and de- 

 coloration could often be observed to commence at one end of the 

 corpuscle and pass towards the other end. After the corpuscles had 

 burst, the nuclei were left stained of a deep yellow colour, and show- 

 ing a beautiful intranuclear plexus of fibrils. Many nuclei were seen 

 with the collapsed envelope and stroma of the corpuscle still adherent 

 to them. After a time the collapsed envelope and stroma often 

 became slightly stained of a yellow colour. 



Citric Acid. 



The action of a 12 per cent, solution of citric acid was in every 

 respect the same as that of tartaric acid. 



Formic Acid. 



On irrigation of a drop of blood with a 12 per cent, solution of this 

 acid, the nuclei became distinct, and many of the corpuscles very 

 soon became globular, gave way at one side, and became decolorised. 

 The giving way was accompanied by a recoil or jerk. The nucleus 

 sometimes escaped, but was generally surrounded by vestiges of the 

 collapsed envelope, and of the stroma of the corpuscle. These effects 

 were only seen in those corpuscles which first came under the influence 

 of the reagent. In those corpuscles which were least exposed to the 



