Action of certain Reagents upon Coloured Blood- Corpuscles. 119 



Benzoic Acid. 



This acid is soluble to the extent of 1 in 200 parts of water. A 

 saturated solution causes the nuclei to become distinct and many of 

 the corpuscles to become spherical. The contents of the stroma 

 of the corpuscle gradually pass out through the membrane and the 

 field of the microscope becomes covered with granular debris, which is 

 in greatest abundance close to the corpuscles. The latter at length 

 become quite clear, except for a few granules here and there in the 

 stroma. The nuclei are distinct and of a bright yellow colour and are 

 generally oval and more or less irregular in outline, but sometimes 

 spherical. A double contour-line can nearly always be made out both 

 around the nucleus and body of the corpuscle. Some of the nuclei 

 show an intranuclear plexus, others are smooth and homogeneous. 



Salicylic Acid. 



A saturated watery solution of salicylic acid caused the corpuscles 

 to swell up rapidly and become globular, the nuclei at the same time 

 becoming tinged yellow. 



In a very short time the corpuscles begin to elongate one after 

 another, with a sudden jerk. ~No visible break could be observed in 

 the side of the corpuscle, although the nucleus at the moment of 

 recoil was often observed to pass out through the side of the cor- 

 puscle. The field of the microscope quickly became covered with 

 yellowish debris — the contents of the stroma of the corpuscles — while 

 the perinuclear part of the corpuscles became decolorised. Some of 

 the nuclei were smooth in appearance, and bright yellow in colour ; 

 others showed beautifully the intranuclear plexus of fibrils, with 

 narrow meshes ; and still others had become swollen up to about twice 

 their normal dimensions, and exhibited a wide-meshed plexus in their 

 interior, due no doubt to the separation of the fibrils by the swelling 

 up of the interfibrillar substance. Those nuclei which showed a 

 plexus in their interior were observed to be bounded by a doable 

 contour-line, tinged of a yellow colour. A similar line indicated the 

 position of the envelope of the corpuscle. Many free nuclei were 

 observed, and some with the collapsed envelope and stroma of the 

 corpuscle still clinging to them. 



Other nuclei were noticed half within and half without the cor- 

 puscle. When the effect of the reagent had been more gradual, the 

 perinuclear part of the corpuscle was granular and darkened in 

 colour. The nucleus was pale — slightly tinged yellow — and showed 

 an intranuclear plexus. 



With this acid, as with many others, we frequently observed indi- 

 cations in the nuclei as if they were dividing, and we recall the 

 observation of Preyer, that in the breeding season, he observed that 



