84 ANDREWS. 



nature, the cells passed soon after through a great change of 

 viscosity, visibly relaxing. They then showed rather marked 

 change of contour, and afterward renewed their spinnings until 

 once more connection was reestablished amongst themselves, 

 when by degrees they drew more and more closely together 

 until they touched. The walls then coalesced and the two, 

 four, six, eight, twelve, or more, cells were again a solid mass. 

 After such coalescence there came on always a marked increase 

 of viscosity in the whole mass, and markedly greater resistance 

 to pressure. Just before renewed division this would again be 

 somewhat relaxed, and the spinning phenomena more active. 



During the past two years I have observed in the blastomeres 

 of frogs' eggs the same increase of resistance under gradual 

 pressure, and similar changes in some few of the lobose bands 

 of protoplasm or ectosarc by which, when separated, they had 

 restored connection. 



[90] There can hardly be a doubt but that there is here shown 

 a definite physiological resistance to certain adverse mechanical 

 conditions in environment ; that the living substance responds 

 in character of its own powers to stimulus of a given sort ; 

 that this response is to conditions which are probably new to 

 the substance, and is, moreover, contrary in its nature to that 

 given by purely physical foams. 



For, had the substance thus dealt with been an inert, purely 

 physical, foam, bridges and bands of it connecting the cells 

 would have shown a most contrary series of reactions. Under 

 pressure that forced apart the cells, they would have become 

 more tenuous and longer, as well as less distinct and less 

 refractive optically, and the pellicular substance also would have 

 become stretched and less refractive. The peripheral processes 

 would have been increased in length and mass, and also, no 

 doubt, in number. 



The phenomena of the living eggs were on the other hand 

 exactly such as characterize all protoplasm, whatever its form 

 or position, in contractile states and especially during active 

 contraction. Further proof that this was actually the case was 

 given during the usual drawing together of separated sister 

 cells after cleavage was ended. First the cells usually rounded 



