f 



I 

















Dr. A. Gruber on Protozoa. 315 



XLI. — Investigations upon some Protozoa. 



By Dr. August Gruber. 



[Plate XIII. ] 

 [Continued from p. 276.] 



II. On some Infusoria. 



* 



1. Spongomonas guttula. 



In his comprehensive and exceedingly meritorious general 

 work upon all the known Infusoria, Saville Kent* has made 

 known a new species of the genus Sponyomonas, which is 

 chiefly distinguished by the circumstance that it constructs 

 larger sac-like colonies. In a small aquarium , in which the 

 water had been putrid for some time, I accidentally found a 

 large quantity of brownish spheres, which, on closer exami- 

 nation, also proved to be produced by small Flagellata. 



The colonies of Sponyomonas guttula, as I shall name the 

 j Infusorium, are vesicles, either quite spherical or folded by 



the falling-in of the surface, which adhered partly to the walls 

 of the glass, partly to all sorts of objects contained in it, and 

 in part also hung from the surface of the water. 



At the side by which they are attached there is an aperture 

 through which we can see into the interior of the hollow ball. 

 Their size was very various ; but I have never found one 

 larger than that represented of the natural size in fig. 8. 



As ill Kent's Sponyomonas sacculus, the brown colour is 

 due to small granules, which, held together by gelatinous 

 matter, form the principal mass of the colony. The indivi- 

 dual Infusoria are not irregularly distributed over the surface 

 of the ball, but planted at regular distances in the jelly. 



Each of the minute Flagellata is placed at the end of a 

 tube which it has itself secreted. These tubes, however, are 

 not separated from each other, but firmly amalgamated toge- 

 ther, as in the gelatinous spheres of the Ophrydinife. These 

 canals arc most distinctly seen at that part of the vesicle 

 where the aperture is situated ; for there we may trace them 

 throughout their whole length. ' In proportion as they become 

 longer the whole vesicle also increases in dimensions. 



The origin of these colonies is not easy to explain ; and it 



8< ms to me the most probable supposition that the Flagellata 



dispersed in great quantities through the water, settled upon 



air-vesicles which adhered to the walls of the aquarium or 



J floated at the surface of the water. In somewhat putrid 



• • A Manual of the Infusoria' (Loudon, 1880-81), pp. 288, 280, pi. xii. 



figs. 17-23. 



22* 



/ 



