Crystal Cyst Formation in Parenchymatous Tissue. 167 
case described by Heidenhain with conditions prevailing in the ordinary 
calcium oxalate crystal cell, it is very difficult to compare the behaviour of the 
nucleus in the former case with that of the crystal cyst. In the formation of 
the cyst cell an activity in different directions takes, place, i. e. a fusion of 
a whole cell complex occurs whereby the control of the movement or position 
of the nucleus in the original young cyst cell is very often lost. 
Other abnormal conditions inside and outside the original cyst are 
added, i. e. the accumulation of the secreted material in the cell body, which 
is of course pronounced in the fusion with neighbouring cells; the study 
of the behaviour of the nucleus is thus much more difficult. Under 
these circumstances an additional and essential factor should be kept in 
view, which is certainly of some importance in regard to the behaviour of 
the nucleus in the cases of function of crystal substances in cells, generally 
speaking. 
In the crystal cell there is an accumulation of secretion material 
which is evidenced by the crystallization of the oxalate substance by which 
water molecules are stored. The protoplasm is consequently deprived of 
molecules of water. Finally, the nucleus is also influenced by the with¬ 
drawal of water from the protoplasm, whereby the regulatory phenomena are 
disturbed. 
There also can be no doubt that the stimulus, be it an external 
or an internal one, first affects the protoplasm and then directly or 
eventually the nucleus. However, the irritation may influence only the 
plasma or both it and the nucleus. This of course depends entirely upon 
the quality and the quantity of the stimulus. The changes in form of the 
nucleus are therefore brought about indirectly and do not result from the 
direct effects of the irritation. 
Fuchs (13) found in the raphid cells of Galium Mollugo, Asperula 
tinctoria,dec\& also of Hydrangea Hortensia and Aloe, that the nucleus in the 
crystal cell is of an elongated and more or less spindle-like form, whereas 
the nucleus in Mesembryanthemum crystallinum was round and entirely 
indistinguishable from the nuclei of other cells. It may be that in the 
latter case the nucleus was only temporarily round, and had not yet been 
influenced by the irritation or would not be influenced at all. From the 
work of Fuchs it does not appear whether or not the nucleus keeps its 
round form or whether it changes in form later. 
As far as can be ascertained, no one has undertaken to systematically 
observe the behaviour of the nucleus during the development of such crystal 
cells. In any event, the observations of Fuchs are not sufficient to lead to 
any definite conclusion. 
The temporary spherical form of the nuclei of the crystal cysts in 
Anthurium offers an interesting example of changes of form under the 
influence of irritation stimuli. After the fusion of the nucleus of the 
