ON DIPLOZOON NIPPONICUM, N. SP. 177 



to have taken place in the smaller excretory vessels of the Distomes, 

 I must leave entirely undecided, with the single remai'k, however, 

 that in Diplozoon I have observed no trace of nuclei in the wall. 



The capillaries, furnished like the larger vessels with a distinct 

 wall of compact refractive membrane, proceed from tlie smaller 

 branches of the main vessels, and continue throughout their whole 

 course without undergoing any perceptible diminution of their calibre. 

 They are especially abundant in the layer of the mesenchyma just 

 under the muscular wall of the b()dy. The}' do not, like the branch- 

 es of the larger vessels, anastomose with one another, and no vibratory 

 movement is to he observed within. They branch freely, and each of 

 the branches ends with a minute funnel-shaped enlargement (Fig. 15), 

 within which is to be seen an active vibratile flap, the so-called 

 " Wimperflamme." Various structures have been described in con- 

 nection with these funnels, but, although I directed my utmost atten- 

 tion to the point and applied the best lenses at my disposal (Seibert 

 apochr. syst., 4inmx8),I could not observe any of them. The 

 majority of the writers wdio have specially investigated this subject 

 seem to agree in excluding any direct communication between the 

 cavities of the funnels and those of the surrounding mesenchyma. 

 In this respect, however, Fraipont makes an exception. He observed 

 "fenêtre ovale" in the wall of the funnel, by which its cavity was 

 put in direct connection w^ith the surrounding pseudocoel. I had at 

 first supposed the end of the fiumel completely closed ; but on 

 repeated observations with the apochromatic system of Seibert, it 

 seemed to me very probably open, and to communicate with the 

 cavities of the mesenchyma. I have not observed any of those peculiar 

 cells described by preceeding writers.^' 



1) On reading Wright and Macallum's description, the question naturally arises if the 

 writers have not mistaken the ciliated portions of the capillaries, such as have been described 



