Opalina. 213 
These spherules or drops of liquid in the ectosare stain intra 
vidam with neutral red (darkly stained after half an hour), methylem 
blue (deep stain), toluidin blue (deep stain) (Fig. 20, Pl. XV). They 
do not stain intra vitam with Congo red, indigo-carmine, methyl 
violet, dahlia, Bismarck brown, gentian violet, thionin or eosin. 
With methylen blue and toluidin blue the anterior end of the body 
remains almost entirely unstained, showing either that the ectosare 
spherules are wanting there, or are in a different condition. The 
study of sections shows that the ectosare spherules are very small 
in that region. After ztra vitam staining with toluidin blue (Fig. 20, 
Pl. XV) one finds a few bodies, larger than the ordinary ectosare 
spherules, stained a much darker blue. These are evidently in a 
different condition, if they be not of a wholly different nature. It 
is probable that these larger, darkly staining bodies lie in the outer 
part of the endosarc. Compare the results, obtained by staining 
with iodine and with Fiscuer’s glycogen stain (page 218). 
The statements in the last paragraph apply only to true intra 
vitam staining, the animals remaining alive and active. As the 
animals become inactive and die, the ectoplasmic spherules com- 
mence to stain with methyl violet, though later they again fade. 
If one sections animals which have been fixed in corrosive subli- 
mate-acetic acid and stains the sections with the same dyes 
that were used for intra vitam staining, somewhat different re- 
sults are obtained. Methylen blue stains the ectosarc spherules 
green, not. blue as in life; methyl violet colors them violet like the 
protoplasm; dahlia stains them purple; gentian violet stains them 
pale violet; thionin stains them green; Bismarck brown colors them 
brown; though the last five reagents left these spherules unstained 
in the living animal. In the table in the appendix the color re- 
actions of the different parts of the body to all the stains used are 
given. I would call attention to the fact that with safranin and 
light green the ectoplasmic spherules are all colored green, though 
with safranin when used alone they stain a good red. 
The ectosare spherules show little structure with most stains 
(Figs. 4, 7, 8, 9, 14, Pl. XIV). With dahlia some of the larger, 
more faintly stained ones show granules which seem to be peripheral 
(Fig. 7). Iron-haematoxylin when insufficiently extracted shows the 
spherules apparently homogeneous (Figs. 4, 9), but after longer de- 
colorization one often finds them showing clearly the presence of 
peripheral granules and even apparently alveolar structure (Fig. 5). 
When found, these indications consist merely of faint dark lines 
1a* 
