Development, and Structure of the Vegetable Cell. 289 
was only indistinctly perceptible. On three occasions I saw two of 
these globular ciliated bodies come into contact (fig. 54), adhere 
to each other, coalesce at the point of contact, and form a single 
motionless body. At the same time the whole of the cilia on 
the free surface very rapidly shortened, leaving the periphery 
completely smooth, whilst the granular colourless membrane 
became transparent, and constituted a structureless and rather 
thick envelope around the two coalesced bodies, which had now 
become completely united into a single, rather irregular, oblong 
body. 
After a time this structure became flattened on the under 
surface; the red granular contents (of whose origin from two 
distinct masses no trace could any longer be discerned) now again 
underwent division into two portions, which were coated exter- 
nally with red vesicles resembling oil-drops. Subsequently, 
within each of these segments, two globules separated, and in 
the place of these, again, numerous smaller ones made their ap- 
pearance, a complete process of segmentation taking place, such 
as occurs in ova after impregnation. In consequence of this 
continued development of endogenous cell-generations, the ob- 
ject of which is doubtless the production of higher organic 
compounds, the thick-walled envelope, which is constantly un- 
dergoing certain changes of form, becomes now filled with a great 
number of small vesicles, which shimmer through the external 
red layer, consisting apparently of oil-drops, which lie immediately 
contiguous to the colourless membrane (PI. VII. fig. 55). In 
the course of two days there is a distinct constriction of one 
half of the contents into several portions, as in the formation of 
an annulose animal (fig. 56). 
The further development of the larva beyond this stage has 
mostly failed in my hands: in only one instance did it proceed 
to the third day ; and even in this the animal escaped from the 
sac before its full form was visible (probably owing to the pres- 
sure of the glass cover, in consequence of the evaporation of the 
water around the object), in the shape and manner represented 
in fig. 57. 
Unfortunately this phase of development is still so mcomplete 
that it is not possible to determine accurately what animal it 
was. I am disposed to regard it as one of the Rotifera, of the 
genus Rattalus, specimens of which were abundant around. 
Nevertheless the above marvellous metamorphosis, followed out 
as it was for some time by myself, claims the attention of zoo- 
logists. I have to add to the foregoing fact, that a reddish- 
yellow-coloured Ameba is to be found living within the joint- 
cells of Gidogonium whilst still filled with chlorophyll, although 
more or less diseased, and that this being seems capable of 
