204 Prof. Allman on the Occurrence of Amebiform Protoplasm, 
The lateral nematophores (2) consist, like the mesial ones, of 
tubular processes from the chitinous periderm, and of peculiar 
contents ; but while the mesial nematophores are formed by a 
set of azygous appendages, the lateral ones are, on the other 
hand, arranged in pairs, each pair consisting of two processes, 
which are given off, exactly opposite to one > another, from the 
sides of the branch, nearly on a level with the orifice of every 
hydrotheca. The chitinous tubes communicate at their base 
with the cavity of the tubular periderm of the branch, and open 
by an oblique aperture at their free extremity. 
The contents of the nematophores consist, in both cases, of a 
soft granular mass, which is continuous below with the ectoderm 
of the ccenosare, and, just behind the terminal aperture, ends in 
a bulbous extremity (c), in which is immersed a cluster of large 
fusiform thread-cells. 
In those nematophores which lie along the mesial line, the 
tubular sheath is furnished, as has just been said, not only with 
a terminal aperture, but also with a lateral ene, through which 
its cavity communicates with that of the hydrotheca. Through 
this aperture the soft granular mass which fills the tube of the 
nematophore has the power of emitting very extensile and muta- 
ble processes, which project into the cavity of the hydrotheca. 
These processes (d’) consist of a finely granular substance, which 
undergoes perpetual change of form, “being at one time broad 
lobe-like extensions, at another longer and more cylindrical, 
sometimes more or less clavate, occasionally irregularly branched ; 
while, again, they can be entirely withdrawn (d), so as to leave no 
apparent trace of their existence. In short, they comport them- 
selves in every respect exactly like the “ pseudopodia” of an 
Ameba, which they also resemble in their structure; for they 
consist of a simple protoplasm composed of a transparent semi- 
fluid basis, in which minute corpuscles are suspended. 
Those nematophores which, instead of being situated on the 
mesial line, are arranged along each side of the branch, have 
their contents quite similar to the others, and send out from 
their terminal aperture similar pseudopodial processes (e), which 
are then projected freely into the surrounding water. I have 
never witnessed the emission of pseudopodia from the terminal 
apertures of the mesial nematophores. In no case do the thread- 
cells appear to be carried out in the pseudopodia. 
It would thus seem that the contents of the nematophores in 
Aglaophenia pluma consist of a true sarcode or protoplasm ; and, 
except in the fact that this protoplasm contains a cluster of 
thread-cells immersed in its substance, it appears in no re- 
spect to differ from that which constitutes the suneiaees of an 
Ameba, 
eS ee en 
