EFFECT OF ARTIFICIAL MEMBRANE FORMATION 



75 



When the disintegration has once commenced, it continues 

 until, after a certain time which varies inversely with the 

 temperature, the whole egg is disintegrated. Fig. 23 represents 

 an egg a few hours after artificial membrane formation, in 



Fig. 23 



Fig. 24 



Fig. 25 Fig. 26 



FIGS. 23-26. Disintegration of the sea-urchin egg after artificial membrane 

 formation, if it is not submitted to treatment with a hypertonic solution or an 

 inhibition of oxidations. 



which the nuclear spindle is visible. It did not develop farther, 

 but a little later a few clear drops (Fig. 24), resembling polar 

 bodies, appeared to exude from the egg; I suspect that this 

 extravasation of drops took place in the equatorial plane. This 

 disintegration then proceeds farther (Fig. 25), until finally the 

 egg is almost completely destroyed (Fig. 26). 



