298 LILIAN J. GOULD. 
capsule. The character of the protoplasm was somewhat 
different without the ring from that within. External to the 
ring it was highly vacuolated; from the periphery of the 
animal inwards areas containing very few nuclei or vacuoles, 
but consisting almost entirely of small vesicles, extended 
nearly to the boundary of the ring, in some places running 
quite up to it. Fig. 1 shows a whole section about the middle 
of the series, drawn without details, showing merely the gene- 
ral appearance and size of the ring, with the nuclei and largest 
vacuoles. The dotted regions represent the vesicular areas. 
The ring itself exhibited the extremely fine alveolar structure 
above mentioned. Internal to the ring I could make out 
nothing more than a very finely granular appearance of the 
protoplasm; alveoli, if present, must have been infinitely 
small in diameter. Fig. 8 is a high-power view of a portion 
of the ring; the area marked out by dotted lines is represented 
on a much larger scale in fig. 10, to show more accurately the 
character of the alveoli. The capsular appearance was not due 
to the effect of semi-penetration of the osmic acid used in kill- 
ing, since an individual treated with the same reagent for the 
same length of time, but stained with picro-carmine, showed 
no trace of the structure. Some specimens of P. palustris 
obtained later, which were killed with alcohol and stained in 
bulk with carm-alum, showed a slight tendency to the same 
appearance; there seemed to be a drawing together or central 
concentration of the protoplasm, though there was no definite 
ring formed. But these individuals presented, in the living 
state, quite a different appearance from those examined pre- 
viously. They were shrunk up into a globular shape, were 
brownish in colour, and perfectly quiescent, so that on first 
examination they seemed to be dead. But after they had 
been under the microscope for a long time, they gradually 
began to assume a more normal appearance, and very slowly 
put forth pseudopodia. It was a condition suggesting en- 
cystment, but no definite cyst-wall was found. It appeared 
to me possible that these individuals were in a stage leading 
on to, or nearly connected with, that seen in the first-mentioned 
