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G. L. Kite 



of the cytoplasmic gel. Yet it seems likely that all such structures 

 as granules and globules must be considered as having separated 

 out of the disperse phase and to be therefore of the nature of 

 suspensions. The living cytoplasm, then, is an apparently homo- 

 geneous and very viscous gel in which microsomes and globules are 

 suspended. 



If the nucleus of the immature starfish egg be dissected out in sea 

 water it undergoes no appreciable change. Dissection of the highly- 

 translucent nuclear membrane shows this structure to be a very tough 

 viscous solid, and, in fact, closely allied physically to the vitelline 

 membrane and not at all the delicate structure of the conventional 

 descriptions. With the exception of the nucleolus, the nuclear sub- 

 stance is all in the sol state. The nuclear sol is apparently a homo- 

 geneous liquid. The nucleolus is a small mass of quite rigid and 

 cohesive granular gel that is suspended in the nuclear sol. 



The polar body is a granular, elastic and highly viscous gel. 



In order to make it possible to observe the structural components 

 of the starfish egg and of the eggs of other common marine inverte- 

 brates, without having to use my tedious methods, vital staining was 

 resorted to. The jelly envelope can be stained a beautiful light blue 

 with dimethyl-safranin-azo-dimethyl-anilin; the vitelline membrane 

 a very dark blue with isamin blue; the globules or droplets from yellow 

 to orange with vusuvin; and the extremely small granules a slate blue 

 with diethyl-safranin-azo-dimethyl-anilin. 



The dead or dying asterias egg shows remarkable morphological 

 changes. The whole egg becomes almost opaque. The cytoplasm 

 separates into a large number of more or less rounded masses which 

 still adhere to each other. Such masses vary greatly in size, some 

 being as small as five microns in diameter. If the formation of such 

 small masses be observed, one is easily misled into believing that 

 fusion of the globules is occurring. Dissection of such a mass frees 

 the original globules. The dead gel does not stick to a glass needle 

 and can no longer be drawn out into strands; it has lost much of its 

 viscidity and cohesiveness. The nuclear fluid has set and the result- 

 ing gel is more voluminous than was the nuclear fluid in the living egg. 

 The nuclear membrane shows little change in its physical properties, 

 while the nuclear gel is elastic and quite viscous and granular. The 

 physical properties of the dead nuclear gel are very similar to those 



