188 THE M1CROSCOPIST. 



cause a precipitate in them. They are tinged by neutral 

 solutions of carmiuate of ammonia. One-half to 1 per 

 cent, of salt added to the staining fluid causes the nuclei 

 only of Amphibian corpuscles to be stained. Chloroform, 

 tannin, and other reagents, produce various changes, 

 which suggest a wide field of research connected with 

 Therapeutics. 



The old opinion of the structure of red corpuscles rep- 

 resented them as vesicles consisting of a membrane and its 

 contents, but Max Schultze, in 1861, showed that a mem- 

 brane was not constant. This may be verified by break- 

 ing them under pressure. 



Briicke's experiment on the astringent action of boracic 

 acid on the blood of Triton, repeated by Strieker and Lan- 

 kester, shows the red corpuscles to possess a double struc- 

 ture. There is a body, called (Ecoid ; a porous, non-con- 

 tractile, soft, transparent mass ; and a retractile substance, 

 or Zooid, containing the heemoglobulin, which fills the in- 

 terspaces of the CEcoid. The Zooid seems identical with 

 simple cell-substance, or bioplasm. 



3. Colorless, or White Corpuscles. These appear to be 

 simply masses of bioplasm of various sizes. Some are 

 quite small, and many are larger than the red corpuscles. 

 Their number is much smaller than the red disks, being 

 about 1 to 350, or even less. In leucaemia and other dis- 

 eases their relative number is much greater. In the blood 

 of cold-blooded animals, and in that of vertebrata, if the 

 normal temperature is continued by means of a warm 

 stage, the amoeboid motions are quite perceptible with a 

 high magnifying power (Plate XVIII, Fig. 139). They 

 may also be seen to take up small particles of matter into 

 their interior, such as cinnabar, carmine, milk-globules, 

 and even portions of the red globules. 



Both red and white cells are forced through the unin- 

 jured walls of small vessels by impeded circulation, but 

 the white cells thus migrate, by virtue of their vital con- 



