Protoplasm by Aid of Microdissection. 283 
The nucleus then partially collapses, throwing the nuclear surface into 
irregular folds/ This is, of course, only evidence of the fact that the 
nuclear membrane, like the plasma-membrane, may at times exist in the gel 
state, although here I doubt very much if a nucleus subjected to such 
treatment would long remain normal. The folded nuclear surface may be 
coagulated. 
Whether or not we are justified in calling the nuclear membrane 
a morphological structure, any- more than that expression is applicable to 
the cytoplasmic membrane, is doubtful. Chambers ( 9 , p. 10) describes an 
experiment in which he cut the nucleus of an ovum in two. Each part 
The isolated, degenerate Amoeba nucleus from which the coagulated nuclear 
membrane has been partially separated. 
rounded up into a droplet. On coming in contact the droplets ran together. 
This observation restricts our notion of a morphological structure as applied 
to fluid membranes . 1 
The accompanying figure illustrates how nicely the nuclear membrane 
can be torn off after isolation, and hence after degeneration of the Amoeba 
nucleus. Staining with methyl blue intensifies the delicate membrane. 
The nuclear substance after isolation degenerates into a coagulum 'into 
which the microdissection needles are placed. As the needles are separated 
the nuclear membrane tears off as a thin though quite resistant veil. 
Physical Chemical Evidence bearing on the Existence of a Plasma - 
1 Botanical cytologists, working on fixed and stained material, have viewed the nuclear 
membrane as a very definite and readily distinguishable structure (when dead). Mottier (27, p. 191) 
describes how the nuclear membrane of pollen mother-cells of Lilium appears to be made from the 
fibrillar kinoplasm, and Yamanouchi (47, p. 431) describes how 1 the membrane of the original 
nucleus in the tetraspore mother-cell (of the red seaweed Polysiphonia) persists through the two 
mitoses 
