52 M. Ehrenberg*s Researches on the Irifusmia. 



N. ornata, and Bursaria vernalis. He could best distinguish 

 this apparatus in the first of these ; and the details which now 

 follow are principally supphed by that species. 



In all young specimens of the Nassula elegans, which are nei- 

 ther too pale nor too much shrunk, may be discovered a beautiful 

 violet spot, placed in the anterior and back part of the body, op- 

 posite to the dental cylinder of the mouth. This part, though 

 higher than the mouth, cannot be considered as the head, be- 

 cause the intestine is ramified within it; it is to be considered 

 as a protuberance placed there, which, however, leaves the gene- 

 ral form of the animal, regular and cylindrical. It is irregular, 

 almost square, and as large, frequently, as the ridge itself. This 

 spot is formed of a great number of small violet globules, very 

 unequal in size, or rather of a great number of colourless vesicles 

 filled with a violet-coloured liquid. Proceeding from this point, a 

 simple canal may be seen, resembling a string of pearls, running 

 along the back, in which the violet coloured matter is carried to- 

 wards the posterior part of the body. It is only in the last third 

 of the body, that a direct union seems to exist between this 

 canal and the vesicles or stomachs of the animal ; for, in this point, 

 the violet colour of the liquid shews itself altered, and mixed 

 with a litde foreign matter. In truth, there may be often 

 remarked the same nutritive substances, such as fragments of 

 oscillatories and vacillories, in this part of the canal, and in the 

 stomach. In all these infusores, the violet matter is found to be 

 discharged at the vent, placed at the posterior part of the body, 

 either pure, or mixed with nutritious matter, or with the excre- 

 menta. The violet vesicles in the posterior part of the body 

 have always appeared in greater proportion than any other mat- 

 ters : the evacuation of the former into the latter, and their con- 

 sequent augmentation, has been often witnessed. At first sight 

 it appears as if these little beings had received as nourishment 

 this violet-coloured matter ; but this is not the case ; and, wholly 

 peculiar in its nature, it proceeds from themselves alone. It 

 would appear that the vesicular mass which is placed in the pos- 

 terior part of the neck in the Nassula elegans, is the secretory 

 organ of this liquid ; for vessels have never been observed to ter- 

 minate in this mass, and all the organs surrounding it are trans- 

 parent and colourless. Sometimes these vesicles were the only 



