No. 4.] HIRUDINEEN STUDIEN. 2 I I 



In Clepsine the funnel consists of three cells, two crown 

 cells and one peduncle cell. The crown cells are differently 

 shaped in different species, but they all more or less resemble 

 the crown cells of Nephelis. The peduncle cell is one long 

 cylindrical cell with an intracellular lumen, which lumen is 

 lined with long cilia. 



The crown cells are situated opposite each other on the outer 

 end of the peduncle cell, and the whole funnel crown therefore 

 resembles the letter T. 



I have been fortunate enough to determine the mode of 

 growth of the funnel cells by dissecting out funnels of very 

 young and of very old specimens. 



The vesicle, which is the second important part of the funnel 

 apparatus, has the same appearance in all the leeches. I pro- 

 pose for it the term " receptaculum excretorium." It is a 

 hollow vesicle, the walls of which are composed of flattened 

 connective-tissue cells, and it is only open toward the central 

 opening of the funnel crown, and closed in all other places. 



The connection of this vesicle with the funnel crown cells 

 has been generally misunderstood. 



The connective-tissue wall of the receptaculum is continuous 

 with a connective-tissue membrane covering the entire outer 

 and under surface of the crown cells in Nephelis and envelop- 

 ing the whole peduncle cell in Clepsine. Thus the ciliated 

 funnel crown is entirely wedged in with its unciliated surface 

 into the receptaculum, as the petals of some flowers are 

 imbedded in the calyx leaves. 



In very young funnels of Clepsine I have found that both 

 the peduncle cell and the receptaculum are extremely minute, 

 the receptaculum being hardly demonstrable, and thus the con- 

 clusion was easily drawn that this receptaculum is only a by- 

 product in the process of growth of the funnel proper, growing 

 with the increase of excretion (see Physiology of Excretion). 

 That the receptaculum is a hollow vesicle filled with debris was 

 proved by pricking it with a needle, when the contents were 

 seen flowing out, while the walls collapsed. 



The funnel of Nephelis lies in the first ampulla of the seg- 

 ment, whereas in Clepsine the position of the funnels is very 



