166 Samuels.—A Pathological Anatomical Study of 
substance within the cell. At the appearance of the vacuoles the nucleus 
is pushed aside. Crystal formation influences the position of the nucleus, if 
not directly, at least indirectly. It is a fact, however, that the position of 
the vacuoles depends entirely upon the physico-chemical conditions, while 
the position of the nucleus is a purely physical or chemical phenomenon. 
The nucleus of an ordinary crystal or raphid-forming cell has, for this 
reason, a position adjacent to the wall; in fact, along the longitudinal wall. 
It is very seldom seen at either of the ends. However, in the cyst cell the 
nucleus may frequently be observed at one end of the cell. The large 
hypertrophied nucleus is always in contact with the crystal or with the 
raphid colonies which lie in various directions, though masses of protoplasm 
may often be very dense and concentrated. 
The nucleus in a cyst cell differs in its position from an ordinary prism 
or raphid cell, in that in the former there results a general physiological 
influence radiating towards the nucleus, equal in all directions, whereas in 
the ordinary prism cell the influence is exerted outward from the point on 
the cell wall at which the nucleus lies. 
The fusion of adjacent neighbouring protoplasts with a particular 
protoplast creates a certain pressure upon the nuclear mass of the latter, 
thus causing it to assume a position which depends upon the direction of the 
pressure exerted by neighbouring protoplasts. The nucleus may be kept 
upright or forced into some other permanent position by reason of the 
mass of calcium oxalate crystals which develop at the centre of the cell. 
The change of position of the nucleus is thus the result of simple mechanical 
conditions. 
Heidenhain (17) and his school observed that in the case of resting 
cells containing a great deal of granular material, the nuclei come to lie flat 
on the lower side of the cell. However, when secretion begins the nuclei 
raise themselves somewhat from the base of the cell, finally becoming 
bubble-like, and do not stain as heavily as before. 
Nussbaum (38) and later Heidenhain (17) declare that these conditions 
arise from purely mechanical causes, because the nuclei in the resting cells 
( Driisenzellen) are mechanically influenced by the accumulation of the 
secreted material in the body of the cell, and make it possible therefore—on 
account of the accumulation of the secreted material—for the nuclei to 
move again into original position of equilibrium. It is doubtful whether or 
not the granular material in the resting cells mentioned by Heidenhain 
should be compared with the calcium oxalate substance discussed here. 
Although it is more or less certain that they are substances of different 
chemical constitution, it is a matter of fact that both are secreted 
material deposited in the cell; they both have a certain influence on the 
nucleus. 
While it is easier to compare to a certain extent the above-mentioned 
