214 GRAF. [VOL. I. 



The cause of the ciliary motion is to be sought in the con- 

 traction of the basal piece, the middle piece playing a nervous 

 role. 1 



This structure seems to be of general occurrence, as the 

 writer found it also, during the last winter, in the ciliated 

 intestine cells of the leeches in all its details. 



The cytoplasm of the ciliated funnel cell is specifically 

 modified, inasmuch as the cytoplasmic threads are arranged 

 parallel to each other, each cilium standing in connection with 

 one of these threads. 



It was observed at first that near the edge of the ciliated 

 cell, where the basal pieces of the cilia stand in communication 

 with the cytoplasmic threads, a great number of little granules 

 are assembled which make this connection obscure, and it was 

 at first inferred that those granules all consisted of food matter 

 destined for the regeneration of the basal pieces. I have, how- 

 ever, after the study of the cells of the intestine in these ani- 

 mals, altered my views in that respect. Only a portion of 

 these granules is food material. The basal piece of the cilium 

 is connected with a fine, short thread projecting into the cell 

 and ending inwardly in a thick granule. (These granules have 

 been discovered and described by me as peripheral organs in 

 other cells.) Only this granule is connected with the cyto- 

 plasmic thread. 



The function of these peripheral organs is a problem of very 

 great interest, but I must leave a discussion of this to a later 

 time, when I have completed my observations. 



The cytoplasmic threads of the ciliated cell are all parallel 

 and show not the slightest connection in their arrangement 

 with the nucleus. 



The nucleus is large, shows a very clear, distinct linin net- 

 work, and the chromatin is suspended in that network in the 

 form of little granules. 



TJie cells of the portio afferens-glandulosa. - - The row of cells 

 forming that part of the nephridium which I call portio afferens- 

 glandulosa presents under the microscope very various struc- 

 tures, according to the place from which they are taken. 



1 See Physiology of Excretion. 



