CHANGES IN THE RED CORPUSCLES BY HEAT AND COLD. 393 



At about 53 to 54 C. (127 to 129 F.),Max Schultze observed 

 the same changes in the blood corpuscles of the fowl as those 

 that have been already described. 



The corpuscles of the blood of the frog at about 45 C. (130 

 F.) become partially maculated and to some extent tuberculated 

 on their surface, others assume the form of a finger-biscuit or of 

 a dumb-bell, whilst a few become oval or spherical. 



7. If blood, contained in a platinum vessel, be alternately 

 frozen and thawed several times in succession, it likewise as- 

 sumes a carmine colour. 



The non-nucleated blood disks are deprived of colour without 

 becoming materially diminished in size, or they will be found 

 to have become spherical, or of smaller diameter, or only their 

 feebly refracting colourless remains can be discovered. 



In the corpuscles of the blood of the frog the nucleus is seen 

 to be surrounded by a pale elliptical or circular area, or the 

 colour of the blood corpuscle appears to be to some extent re- 

 tained. Various forms are also found which appear indented 

 or chipped off; finally here also the blood corpuscles lose their 

 colour. 



The extensibility and elasticity of the uncoloured remains 

 of the blood corpuscles are similar to those of the intact blood 

 corpuscles* 



In frozen blood the nuclei either still resemble unaltered 

 nuclei, only somewhat more sharply defined, or they are sphe- 

 roidal, enlarged, and appear as if composed of a delicate frame- 

 work of highly refractile substance, in the meshes of which a 

 less strongly refractile substance is contained. These spaces 

 are often but few in number. Frequently only a single space 

 is present, in the form of a large vacuole surrounded by a ring 

 of refractile material. These characters of the nucleus deserve 

 attention in regard to facts that will hereafter have to be 

 mentioned. 



8. In reference to the phenomena that are occasioned by 

 the addition of fluids to the blood corpuscles, three different 

 conditions under which they may occur must be clearly distin- 

 guished. The reagent may be intimately commingled with the 



* Rollett, loc. cit., Band xlvi., pp. 74, 75. 



