DIGESTION AND ENDODERM OF LIMNOCODIUM. 129 
particles (such as Protococci and Euglenz) which chance threw 
in its way. In fact, whilst the oral endoderm was full and 
unshed, the ingestive endoderm at the other end of the gastric 
tube was half-starved, with great inter-cellular spaces and eager 
pseusopodial processes, making the best of bad times, and taking 
up materials previously unprepared. 
In those specimens, however, in which the oral endoderm had 
shed its secretion cells, and in which I have supposed that an 
act of swallowing some large prey had recently taken place—in 
these the ingestive endoderm of the proximal end was totally 
changed in appearance. It was gorged with finely granular 
matter; its inter-cellular spaces had almost entirely disappeared 
in consequence of the swelling out of the protoplasm, now 
remarkable for its granular structure. 
The appearance is represented in Plate XI, fig. 5. The 
masses of oval metamorphic products (6 0) are still present, but 
the spaces are reduced to a few small chinks (f). The trabe- 
cule of the framework are no longer visible, owing to the 
swelling of the protoplasm and its granular opaque character ; 
they are concealed by the contiguous edges of the enlarged 
masses of protoplasm. 
I conceive this change to be due to the absorption by the 
ingestive cells of a very abundant supply of albuminous matters 
obtained by the digestion in the cavity of the gastric tube of a 
Daphnia, Cyclops, or some such form. The raw products of 
gastric digestion—partly dissolved partly in the form of fine 
particles—would, it may be assumed, be taken up by the ameeboid 
ingestive cells, just as are the rarer living food-particles in 
times of dearth when so copious a feast as that afforded by a 
Daphnia is not forthcoming. 
As to the return of the ingestive endoderm to its meshwork 
state, with pseudopodia ready for the inception of large food- 
bodies, | have no observations to offer, and I will not speculate 
further upon the possible activity of the ingestive endoderm in 
elaborating the food matters taken in by it. 
It is a matter for regret that the fresh-water Medusa died 
down in the lily-house tank a few weeks after its discovery, so 
that I have not been able to follow up experimentally some of 
the suggestions which the study of the endoderm has afforded 
me. It would be an easy matter with Limnocodium and, indeed, 
with other small Medusz, to determine experimentally the con- 
dition of the endoderm cells of different regions of the gastric 
tube before, during, and after the introduction into that tube 
of an Entomostracous Crustacean. 
The observations and interpretations which I have put forward 
in the preceding pages cannot be regarded as more than an 
VOL. XXI.—NEW SER. I 
