132 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3B Ser. 



visible either inside or outside of the cytoplasmic rope. 

 The latter did not fill the centre of the cell, there being 

 always more or less space not occupied by the thread and 

 the nucleus. 



The nucleus is oval, slightly irregular, with a central 

 contraction. 



A coelomic cell somewhat resembling the nematocyte 

 has recently been described by Edwin S. Goodrich from 

 the lymph of JSnchytrceus hortensis} Mr. Goodrich has 

 figured a number of these cells and demonstrated their 

 minute structure in detail. They differ from the nemato- 

 cyte of Neniatogenia lacuimi var. -panamaensis in having a 

 distinct cell-wall and in having the nucleus placed outside 

 instead of inside of the rope-coil, which is much less regu- 

 larly coiled. 



In the Enchytrmiis cells the rope appears as a secondary 

 structure in the cytoplasm, while in the jSJematogenia cells 

 the rope itself is the cytoplasm and all the cytoplasm there 

 is in the cell. The rope may, perhaps, serve to catch bac- 

 teria, sperm-fragments and other foreign substances in the 

 lymph. The function of the rope in the Enchytrceus cells 

 is unexplainable, unless we presume that it is now and then 

 ejected outside of the cell-wall, serving as a lasso for catch- 

 ing microbes, or for attachment. Cells corresponding to 

 the supposed early stages of the Enchytrceus cells as 

 figured by Goodrich are nowhere to be seen in our Nenia- 

 togenia. Goodrich has also figured (figs. 13 e and 14) cells 

 which greatly resemble the amoebocytes from the Ocnero- 

 drilus lymph ; these cells he describes as thread-cells under 

 the action of water and caustic potash. Similar cells are 

 found in our Neniatogenia, but I do not believe that they 

 are stages of the nematocytes. They are comparatively 

 few in number and are much smaller than the nematocytes ; 

 they also possess a centrally located nucleus, while the 

 amoebocytes figured by Goodrich have no nucleus, but are 

 evidently structures separated from it. No suggestions 

 offer themselves as to the origin of the nematocytes. 



1 Quart. Journ., Mic. Sci., Vol. XXXIX, Pt. i, May, 1896. 



