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1897 ] NOTES ON UROGLENA AMERICANA CALK 109 
it extends entirely around the cell the depression is always 
deepest at the side nearest the periphery of the colony. Thus 
the pressure is greatest from that side, and consequently the 
halves of the dividing cell are gradually turned at right angles 
to their former position, and at the time when complete division 
takes place present their normal appearance, viz., with cilia at 
right angles to the tangent of the ccenobium. The red spot, 
which may have been in almost any part of the cell at first, 
takes its place at the base of the cilia before the final separation 
occurs. A reference to the figures will explain better than any 
description just how this division takes place. 
THE RESTING STAGE. 
Under certain conditions it is possible for an individual cell 
to lose its cilia and, forming a thick gelatinous wall, go into a 
resting stage. When this occurs the chromatophore breaks up 
and the chlorophyll is distributed throughout the entire cell, the 
red spot wholly disappearing. After a time the contents of this 
encysted cell divides and forms two elliptical bodies, and these in 
turn dividing we have four elliptical cells within the original cyst 
wall. Each daughter cell is provided with a red spot and a pair 
of cilia before the wall is ruptured, and so is ready to begin the 
process of division and formation of a new ccenobium as soon as 
liberated. 
When the cells are first set free the chromatophore does not 
occupy the definite position that it does later, but is distributed 
equally throughout the contents of the cell, and is of a brighter 
green color. Oil globules are very abundant at this time, and 
give the cells a decided granular appearance. In a very few 
instances a cyst was observed that had divided into eight daugh- 
tercells. This was mentioned by Kent (5), but does not seem 
to be the ates rule, and (regent ss is not pears & 
; a ie TAXONOMIC POSITION. 
on the large iiaaes of colonies examined, and the inegth 
