868 SYDNEY J. HIOKSON. 



tious. The cords are in some cases fairly compact^ resembling 

 a canal in all respects except the presence of a lumeu; but in 

 others the cells are only loosely connected with one another, 

 become elongated or star-shaped (fig. 26), giving off fine fibrils 

 at their angles. There may be only a single row of oval or 

 cubical cells, or in some cases the row may be drawn out into 

 a chain of elongated spindle-shaped cells (fig. 27). 



(When studying the mesogloea of Alcyonium last December 

 I noticed a number of oral bodies lying in and among the cells 

 [fig. 36, gr.'\ of the endoderraic cords. They may be readily 

 distinguished from the endoderm-cells by their dark but homo- 

 geneous appearance. In one or two instances I have suc- 

 ceeded in making out a somewhat irregular body in the centre, 

 which may be a nucleus. It is difficult to say with any degree 

 of certainty what these bodies are, but it is possible that they 

 may be some form of parasitic sporozoon.) 



(3) The isolated mesogloea cells may be seen in osmic acid 

 and other preparations of fresh sections. They are star-siiaped 

 or bipolar, and are connected with one another by fine fibrils, 

 which branch and anastomose in the homogeneous mesogloea 

 (fig. 26). 



These cells are connected not only with one another, but 

 also with some of the cells of the endoderm cords, and fine 

 fibrils from them may also be seen passing into the endoderm 

 lining the coelentera. 



This account of tlie histology of the mesogloea differs iu many respects from 

 that given by Carl Vogt and Jung. These authors describe numerous small 

 canals on the growing branches of the colony which they call the " Nahr- 

 canale." These end blindly at the periphery, and are continuous with the 

 coelentera. These "Nahrcanale" are probably the same as the "endoderm 

 canals" of my description. 



In addition to these, the authors describe in the substance of the coenen- 

 chym (mesogloea) a network of canals, " Sammelcanale," and capillaries. It 

 is noteworthy that in none of the figures to which reference is made is any 

 lumen drawn in the " Sammelcanale" or capillaries, nor is there any indication 

 in the text that the authors ever saw any lumiua in these so-called canals. 

 They are probably the same, then, as the solid endoderm cords of my account, 

 but quite erroneously described. The network of fine fibrils has not been 

 previously described, and was overlooked by Vogt and Jung. 



