EXPLANATION OF PLATE 86 
S I-I9 have been placed in a series so as to illustrate the ordinary cycle of 
Figure 
development. Figures 19-22 represent the cycle of the microzooids as far as it has been 
observed. 
1G. 
Fic. 
Fic. 
Fic. 
I. 
2. 
A typical resting cell. 
ic PET of division. epa OO a. m. 
longitudinal division completed in one hemi- 
sphere ; the outer layer of the cell- wall has ruptured and the thin inner layer 
Un qs 
. Se aaugnter 
is pushed o 
. Division net comple id. 9:00 a 
. The daughter-cells are clothed with ere cell-walls and their cilia are seen 
a before they break out. 9:15 a. m. 
of the megazooids after swimming freely for an hour or two, has acquired 
a narrow pL RAE border of chlorophyl. 
Am piene older, showing the radial protoplasmic threads and 
widely Pactum cell-w 
uiescent megaz eid in protoplasmic processes have disappeared in 
preparation for division ; the sheaths which invested the bases of the cilia re- 
main 
Four megazouds produced on the second morning. 9:15 a 
m d of the second iria which has deis considerable 
chloropiyi da prominent pyreno 
. The same become quiescent "i divi 
2. Beginning of division to form the third 2m a later?) generation. 8:30 a. m. 
. Continuation of division 
à ht 1l letel id tł cell-wall 
Ceil-Wail,. 
No further growth was i percentile before 2:15 p. m. when the megazooids 
escaped. 
A mature megazooid Sty a vacuolated chromatophore, and finely 
branched protoplasmic susp: 
. The same become quiesc 
The j anent cella formed ; the distended wall of the zooid 
saddened 
. Increase of haematochrom as resting condition advances. 
. The resting-cell ; the cycle of development closed. 
After desiccation or freezing the resting-cell of Fig. 19 forms sixteen micro. 
zooids. 
. Microzooids. 
. A microzooid come to the resting condition. 
. A cell taken from resting vegetation (frozen) producing sixteen large mega- 
zooids in the laboratory. [Dec. 2, New York.] 
A first-generation megazooid beginning to divide. 9:30 a. m. 
: eight microzooids IE I0: 30. 
Fic. 25. Continuation 
vine: 27, 2%. Different forms of microzooi 
Fic. 
G. 29. 
One of these microzooids going into » resting state. 
( 245 ) 
