Crystal Cyst Formation in Parenchymatous Tissue . 169 
living leucocyte during its movements through, the various connective 
tissues. 
In the last case, according to Heidenhain, the change of form is 
effected by intermittent pressure exerted in rapid succession by the plasma 
body. Intermittently this causes considerable surface enlargement and 
surface changes which can only be explained by a high degree of elasticity 
and pliability in the nuclear membrane. It is entirely probable that in the 
case of crystal cysts there is a rapid successive exertion of pressure due to 
the tendency which exists in the young cells to unite with adjacent cells, and 
due also to the same tendency towards union of the nuclei. 
A union or fusion of the neighbouring nuclei with the young cyst 
nucleus can also be brought about, followed by the change in form of the 
large nucleus thus formed. Another important case in which the loss 
of water in the nucleus might play a part is the change of nuclear size in the 
young parenchyma cells. We know, for example, that the cell nuclei, 
together with the nucleoli in the growing cells, which have stopped so as to 
divide, sometimes often grow and then diminish in size later (see Schiller on 
Antithamnion , 48, p. 285 ). Among other examples of nuclear changes 
which, according to Schiller’s observation, depend in all probability on the 
physiological processes in the cell, are those of certain regenerated cells which 
result from injury. In each cell there may be several nuclei lying like 
a string of pearls, one after the other. 
This observation resembles that of Nemec (36) in the plerome of 
Ricinus communis and R. borboniensis . Here these nuclei very often fuse 
together, and from such a mass only one large nucleus results, which may be 
divided again. These nuclei, which lie in a straight line like strings of 
pearls, have, according to Nemec, a nuclear mass in direct relation to 
the size of the cell (pp. 128 - 9 ). Nemec also puts forward another view, 
for he adds: * Wir haben jedoch gesehen, dass Zellen, die mit gleicher 
Anzahl von Kernen versehen sind, eine betrachtliche Verschiedenheit in 
ihrer Grosse zeigen konnen, welcher Umstand mit der eben entwickelten 
Annahme nicht iibereinzustimmen scheint. Aber erstens hangt die Kern- 
teilung auch mit der in der Zelle enthaltenen Zytoplasmamasse zusammen. 
Zweitens, ist diese nicht einfach der Zellgrosse gleich, da die Pflanzenzellen 
zahlreiche Vakuolen enthalten, deren Grosse es bedingt, dass eine recht 
grosse Zelle weniger Zytoplasma enthalten kann, als eine andere ebenso 
grosse oder sogar kleinere ’ (p. 136 ). In other words, the size of the nucleus 
depends entirely on the age or the physiological conditions in and im¬ 
mediately around the cell. 
Schiller stated that all forms of nuclei occur in Antithamnion cresc. var. 
tenuissima and A. plumula, although the cell form remains the same. 
It also appears very clear from the observations of Kohl (20), Van 
Bambeke (64), Lidfors (27), and other investigators, that the nucleus possesses 
