32 ANDREWS. 



[zy] And of all such structure in both classes of animals, 

 modifications of the finer structure for contractile activity as 

 in filose masses and pellicles, persist longest in an active state. 



Of higher forms, I have to offer as evidence in this connec- 

 tion only such as is given by the crab and the frog. In the first 

 class of structures cited, the protoplastic areas, the retention of 

 primitive powers of local adaptation to environmental condi- 

 tions, such as the lowest forms of the substance possess, which 

 include a marked power of swift and stable organization of the 

 elements, and of swiftly varying the viscosity of the interal- 

 veolar stuff ; evidently serves to maintain in such areas a physio- 

 logical existence, independent of the organism which in toto is 

 the food provider for all areas. The limit of existence of such 

 areas must be to great extent the limit of the stored up 

 food, or stimuli, represented by their inclusions. 



In this connection it is hardly possible not to refer to the 

 strange vitality and power of independent existence shown by 

 those curious substance structures, the leucocytes of crab's blood. 

 These, five hours after being drawn from the animal's body 

 while it was in the soft-shelled state, still actively formed colonies, 

 and exhibited free protoplastic phenomena. After general con- 

 nection of the cells had been established throughout the whole 

 by filose processes spun out to excessive delicacy, there was a 

 marked effort on the part of those nearer the periphery to spread 

 themselves out in quite a special way, in flat, almost parallel 

 processes, which again spread themselves out laterally, so as 

 to form sheets and webs and mats of protoplasm ; producing 

 at last a covering, or envelope, of very viscid substance for 

 the whole. A good deal of migration of the individual cells 

 was involved in these activities. The envelope had for the 

 unaided eye a viscid, gelatine-like appearance, and when placed 

 in strong light refracted from the surface. It was at the end 

 of two hours so viscid and firm over the surface of a small 

 wine-glassful of the blood as to sustain considerable pressure. 



The whole mass had now the value of a mass of protoplasm, 

 or even an organism, for the filose processes everywhere bound 

 the once single units into a firm union. The fluid surrounding; 

 them had the value, as to the external pellicle, of a mixed in- 



