C. Dobell and M. W. Jepps 
331 
It will be seen that in this experiment the size of the cyst was un¬ 
changed by fixation, staining, and dehydration; but that a slight dimi¬ 
nution in size was observed in xylol, and a further small reduction in 
balsam. This was clearly due to the circumstance that the cyst wall was 
still partly visible in the former, but completely invisible in the latter. 
The cyst wall remained unstained by the paracarmine; and there could 
be no doubt that the measurements of the “cyst” in balsam were really 
those of the stained protoplasmic contents only. 
Expt. 2. (Cyst No. 7 of Table III). 
Medium in wliich cyst was examined 
Gelatine jelly (living cyst) ... 
Fixative (after 5 mins.) 
Fixative (after hrs.) 
50 % alcohol. 
Paracarmine (20 mins.) 
Absolute alcohol 
Xylol. 
Balsam (immediately) 
Balsam (after 1| hours) 
Dimensions 
12-75/x X 12|a 
12-75/x X 12/x 
12-75/x X 12/x 
12-75/x X 12/x 
12-75/x X 12/x 
10‘5/x X 9/x 
10'5/x X 9/x 
Continuous observation of the cyst showed that the final decrease in 
size took place as follows. In absolute alcohol the protoplasm underwent 
a very slight shrinkage from the cyst wall. (The measurements in this 
medium are those of the cyst wall—not of the contents). In xylol con¬ 
siderable further contraction of the protoplasm was observed, a space 
separating the contents from the wall. In balsam the cyst wall, and con¬ 
sequently the space between it and the protoplasm, became completely 
invisible. The greatly reduced dimensions are therefore those of the 
shrunken protoplasmic contents only. 
Expt. 3. (Cyst No. 13 of Table III). 
In the two previous experiments the staining of the cyst was effected 
with paracarmine (in 70 % alcohol) in order to avoid the tedium of 
transferring the cyst through the many grades of alcohol necessary in 
using a watery stain. We considered it desirable, however, to make 
further observations on cysts stained in haemalum, since this is the 
method we have employed as a routine throughout our investigations. 
We soon found, however, that the cysts were liable to drop out of the 
film when transferred to water, unless the gelatine was thoroughly 
