96 STRUCTURE OF COLORED BLOOD-CORPUSCLES. 



nucleolus, the nucleus, the granules with their threads, are the 

 living contractile matter proper." Aside from some conditions 

 which do not here concern us, he described and illustrated three 

 states of the net- work viz., that of rest, that of contraction, and 

 that of extension. 



A fourth state of the living matter is assumed (hypothetically) 

 by the same investigator, to account for the formation of a flat 

 layer of living matter, such as forms the walls of a vacuole, the 

 membrane of a nucleus, or the outer layer of the whole bioplas- 

 son mass. 



Heitzmann believes that each of these states may at any time 

 change into the other i. e., that the net- work may from the 

 condition of rest be transformed into that of contraction, or 

 of extension, or of flattening, and from each of these into 

 either of the others. At all events, there may arise in the 

 bioplasson body a vacuole having a continuous thin wall, and 

 containing lifeless fluid and detached particles of the living 

 matter. Or, a bioplasson mass may take into its interior foreign 

 bodies by forming around them a cul-de-sac, which then opens 

 toward the center and closes at the periphery, and the net- work, 

 rent during the process, reestablishes itself. Again, a bioplasson 

 body, which by flap or knob protrusion and separation has lost a 

 portion of its substance, as well as the portion detached, may 

 become rounded off the rupture at the place of detachment 

 healing in each case without loss of life. And further, two bio- 

 plasson bodies may coalesce, and a portion of the periphery of 

 each be transformed into the uniting net- work. 



By adopting these views, and applying them to the living 

 matter of colored blood-corpuscles, we may explain the changes 

 which they have been observed to be subject to. What are the 

 changes that occur on the addition of a 40 per cent, saturated 

 solution of bichromate of potash ? I have described indentations 

 and protrusions which either persist or are leveled again ; pro- 

 trusion of knobs, either pedunculated or sessile, which sometimes 

 are so numerous that they surround the body of the corpuscle 

 like a wreath ; decrease of the size of the main* body by detach- 

 ment of knobs j appearance of net- work structure, most marked 

 in the corpuscles which have not lost much of their substance ; 

 vacuolation of corpuscles, and transformation of many of the 

 portions detached into vacuoled globules which increase in 

 size ; finally, change into faint, almost structureless disks, the 

 so-called " ghosts." 



