204 Prof, AUman on the Occurrence of Amcebiform Protoplasm, 



The lateral nematophores (Z») 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 coenosarc, 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 one, 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 while, again, they can be entirely withdrawn {d), so as to leave no 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 

 Amoeba, which they also resemble in their structure; for they 

 consist of a simple pi'otoplasm 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 (<?), 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 

 Aglaophatnia 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 substance of an 

 Amoeba . 



