STRUCTURE OF PROTOPLASM. 317 



The disintegration of a degenerate egg is accomplished . by 

 the matrix going into solution with the sea-water. This may 

 take place with such rapidity as to suggest a miniature explosion 

 of the egg ; or may be delayed and then it usually proceeds slowly , 

 either in spasmodic periods of dissolution, or continuously until 

 the entire granular contents has been disseminated. Often this 

 is never completed. Where the disintegration is instantaneous 

 (Fig. 3) it takes place immediately on the over-ripe egg coming 

 in contact with a needle, or by the egg itself before actual dissec- 

 tion can be got under way. The miscibility of the matrix may be 

 general (Fig. 3), or localized (Fig. i). Where dissolution takes 

 place without dissection some internal pressure, evidently os- 

 motic, brings about a rupture. But it is difficult to see why such 

 a force does not greatly expand so pliable a wall before breaking 

 it. This is not the case. Furthermore, where disintegration 

 has been instantaneous wall fragments are not to be found. 

 When the process is gradual bits of it are only occasionally seen 

 (Fig. 2). There is some reason for believing that the pliable t 

 glutinous wall itself undergoes a change during degeneration of 

 the protoplasm. If it does not go into solution it probably be- 

 comes a soft, inelastic gel. 



A distributed, internal, osmotic pressure would be relieved 

 once the egg-wall had broken at any one point, and one 

 would not expect further eruptions. Quite the contrary is 

 true. There may be a rather general dissemination of granules 

 from one region for several seconds, time enough to relieve any 

 pressure within, and subsequently, other craters break forth as 

 shown in Fig. i. These are localized centers of activity. That 

 scattered regions of the egg contents are in different physiological 

 states is further evident from the fact that certain localities may 

 from the very outset remain inactive, never taking part in the 

 general dissolution of the protoplasm, such as the exposed upper 

 surface in Fig. 2. 



The force responsible for a wild scattering of the inclusions in 

 an ovum is a surface-tension one, due to an extraordinarily rapid 

 miscibility of the degenerate matrix in the surrounding medium 

 of sea-water. 



