No. 493] NOTES ON A SPECIES OF PELOMYXA. 545 
views of its wall. For comparison with the living animal I have 
found it useful to employ surface preparations of specimens 
mounted in glycerine, after killing with acetic carmine or acetic 
methyl green; or surface preparations of specimens killed in 
alcohol and mounted in water. Acetic carmine (45 per cent 
acetic) kills the animal as quickly as an osmic fixative, the out- 
line of the living state being faithfully retained. Alcohol and 
acetic methyl green kill more slowly, the animal undergoing 
some change of shape, which involves especially the peripheral 
region. On addition of these fluids the coarsely granular endo- 
sarc either contracts, or the surface film of the Pelomyxa is 
raised up by absorption of fluid. That the latter is the case, is 
the impression made on one when the animal is kept under 
observation during the action of the fixative — the surface 
seems to rise up often in bleb-like swellings. The result, at 
any rate, is that the clear ectosarcal region, very narrow in 
life, is greatly increased in width, and thus a considerable area, 
exhibiting the fine reticular (alveolar) structure characteristic 
of this region, may be had for study. 
The general endosarc lying between the vacuoles shows the 
greatest abundance of coarse granules so closely set that they 
must obscure whatever finer struc- 
tures are here present. These gran- 
ules very commonly have a diameter 
of one micron, though smaller ones 
of varying size are abundant. 
In sectional view (Fig. 11) the 
walls of many of the larger vacuoles 
seem made up of similar coarse gran- 
ules, arranged regularly so as to form Fic 
. 11. — Part of section. showing 
vacuoles, deeply stained endosarcal 
a smooth bounding surface for the granules, and several deeply stained 
cavity. These bounding granules albuminous globules. Zeiss yy 
* : x 4. Reduced to 24 
are generally about 1 4 in diameter, 
but in places they may be much smaller, ranging down to 
the size of microsomes. Long vacuoles are occasionally found 
somewhat constricted, so as to be incompletely divided up into 
chambers (crenellated vacuoles of Gould, /oc. cz/.), as in Fig. 
II. Intravacuolar strands may be seen in these vacuoles. In 
