1 9 2 o] SEIFRIZ—PRO TOP LA SM 3 8 1 



Prolonged dissection always ultimately causes an increase in 

 the consistency of protoplasm, unless rapid dissolution first takes 

 place. The rate of increase in viscosity varies greatly in different 



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types of organisms, and even in different individuals of the same 

 type. It is surprising how much dissection protoplasm will often 

 tolerate without showing any increase in viscosity or sign of 

 degeneration, but no protoplasm will endure churning by micro- 

 dissection needles indefinitely. The outcome of such ill treatment 

 may be rapid disintegration or a pronounced increase in viscosity, 

 probably gelation. Hyman (13) states that "the injury of cutting 

 may completely alter the physical state of protoplasm, probably 

 in the direction of liquefaction. " This is not true unless the injury 

 is sufficient to cause complete degeneration, that is, death. Injury 

 not resulting in death always causes an increase in viscosity of the 

 protoplasm. In the advent of death liquefaction does first take 

 place, followed by coagulation. 



The injury to an organism undergoing dissection may be 

 general or local; in either case an increase in viscosity results. If 

 the increase in consistency is local, the injured region may be dis- 

 carded, apparently by the organism, although actually the living 

 organism plays only a passive part, or it may be reabsorbed, by 

 reverting to the sol state. If the increase in viscosity is general 

 and pronounced, death follows. 



An Amoeba usually shows little change in viscosity over that 

 of the normal quiescent stage as a result of quite some minutes 

 of dissection. Finally, however, either a sudden and pronounced 

 gelation takes place, or, more often, rapid disintegration results. 

 In Myxomycetes the rate of change in consistency due to physical 

 disturbance is slow and gradual. Ultimately, protoplasm sub- 

 jected to much dissection will always coagulate, unless preceded 

 by rapid dissolution. A coagulum thus formed at death can be 

 cut up into pieces which exhibit none of the properties of the living 

 substance, such as glutinosity, plasticity, elasticity, etc. 



Marine ova are subject to the same pathological changes in 

 viscosity as a result of dissection and aging. The increase in con- 

 sistency from dissection takes place more rapidly than in Myxomy- 

 cete protoplasm. Here again the degenerate protoplasm ultimately 



