Anatomical structure of Aspidogaster conchicola. 515 



large nucleus with its long axis in the direction of the funnel. This 

 I have seen best when I have cut away the foot of the animal and 

 mounted it flattened out and compressed. Then the preparation was 

 thinner with less material to obstruct the light than generally is the 

 case. But I must admit that I have never satisfactorily seen the 

 outline of the funnel cell to which nucleus and cilia belong. The 

 length of the funnel-organ from the base of its cilia to its constriction 

 into the capillary is 10 /n and its greatest breadth 4 i^i. The organ 

 is doubtlessly completely closed there being no inlet at the sides or 

 even through the centre of the cilia-flame. 



The motion of the cilia is distinctly characteristic and not at all 

 to be confounded with that of the ciliary organs in the conducting 

 vessels. Until one has had some experience, however, the funnels 

 may be easily passed over as perhaps only indistinct portions of 

 vessels containing small ciliated organs. It is quite probable that the 

 largeness, plainness and number of the ciliary organs in the vessels, as 

 well as their different sizes and characters have been an obstacle to 

 the discovery of the end funnels. When, however, a person has once 

 clearly seen and considered one of these organs, and especially when 

 he has repeated the process a few times and noted their constancy 

 of size and structure, he will have no difficulty in recognizing them 

 at a glance ever afterwards. Relatively to its surface, the ciliated 

 cone of a funnel is much shorter and broader than one on the wall 

 of a vessel. The former too moves with a steady, graceful, shimmering 

 motion; while the latter moves through a greater distance with an 

 irregular, labored, serpentine motion. In the first we have motion 

 apparently as a swing from side to side like a pendulum; while in 

 the second we see a wave motion from the base towards the apex of 

 the cone. 



I have observed the funnel cilia immediately after they have 

 ceased motion, when they are just as plain as when in motion but, 

 of course, they are much more difficult to find. In them it is more 

 than probable that we have to do with bundles of cilia, but I have 

 never seen frayed- out cilia here as in the vessels. In the dead state 

 they are pointed and palely striated. 



The funnel is situated between cells. I have seen that the 

 boundaries of contiguous cells would meet at this organ although the 

 outlines of those cells could not be fully traced. But to me it is not 

 clear why they have such a regular form, and also their capillaries 

 such a definite, uniform thickness and an exactly straight or a neatly 



