26 Mr. H.J. Carter on Freshwater Rhizopoda 
in the same animal ; and I have already stated that the spherules 
of the nucleus, after passing into the body of D. pyriformis, 
ultimately appear in the watch-glass with ciliated polymorphic 
bodies, whereby we may fairly infer that the same changes take 
place in those of D. compressa. What, then, becomes of the 
“reproductive cells”? in D. compressa? Now, assuming, as we 
have done, that the reproductive cells in D. pyriformis were 
mistaken for large starch-granules, and remembering also not 
only that the spherules were ciliated, but also that dmaebe much 
larger in size were among the contents of the watch-glass (Pl. I. 
fig. 4 a,b), which were inferred to come from the colourless 
specimens of D. pyriformis, in which the spherules had passed 
into the body of the animal, is it not worthy of consideration 
whether the latter (that is, the Amebe) may not have come from 
the reproductive cells? and, therefore, whether the spherules of 
the nucleus may not bear the relation of spermatozoids to these 
reproductive cells? If so, too, in some instances, the granula- 
tion of the nucleus may take place in one, and the formation of 
the reproductive cells (from a larger subdivision of the nucleus) 
in another individual—thus rendering the species dicecious ; 
while others may be both moncecious and dicecious, It 
would be easy for impregnation to take place in the body of the 
Difflugia, where both the spherules of the nucleus and the repro- 
ductive cells might come together in a preeminently plastic state 
for their union, although it be true that in many instances the 
procreative elements of other organisms eliminate themselves 
from the parent and get into the water before this act takes 
place: at the same time here it must occur quickly, or the forma- 
tion of a pellicle over the surface of the protoplasm of the germ- 
cell or sperm-cell (which it does not appear to be in the power 
of either to control) inevitably defeats the process. 
There is another question also which I have not yet been able 
to determine, viz. whether or not the chlorophyll-cells in D, pyri- 
formis and the brown cells in D. compressa are not identical with 
those bodies in the Amwbe, &e., which I have termed “ gran- 
ules” (Annals, ser. 3. vol. xii. p.33 &c.). Inthe amoebous cell of 
Spongilla they are frequently of a bluish emerald-green colour 
under the microscope, and, in some instances, appear to impart 
the green colour to the mass. Again, in Ameba princeps, &e., 
they frequently pass into crystalloids; while [ have seen and 
figured them also in the pseudopodia of Difflugia tricuspis, Cart. 
(Annals, ser. 2. vol. xvii. pl. 7. fig. 80), and in those of Arcella 
vulgaris, Ehr. Yet in those of D, pyriformis and D, compressa | 
have never seen anything but a dense number of fine granules, 
which look like those with which the sarcode is charged, and 
to which I have given the name of “molecule.” Hence I 
