108 DUBLIN UNIYEHSITY 



chrome, is again manifest at this edge or lateral point of view, when it is 

 also seen that each half of the endochrome does not approach the other 

 directly straight, but, at a short distance from the central clear space, 

 they are each somewhat suddenly curved towards each other, and towards 

 the boundary wall, to which they approximate closely at the same side. 

 I have only once or twice seen the base of each half of the endochrome 

 curved towards the cell- wall at opposite sides. Of course the transparent 

 space at each end of the endochrome, bounded by the primordial utricle, 

 is equally apparent in the present view as it was before, and the active 

 granules can be equally well seen exerting their curious motion ; and in 

 addition, owing to the compressed and narrow mass of cell-contents 

 leaving a considerable space, they can not unfrequently be seen at a 

 distance from the end of the joint swimming up and down with a tre- 

 mulous, agitated, fluttering, uncertain motion. Occasionally one can 

 be seen, having travelled up the length of the joint, to escape into the 

 terminal space and join in the active dance of the other granules. Even 

 at the view of the joint, first adverted to (Fig. 1), which exposes the 

 broader diameter of the band of endochrome, and which leaves no room 

 for them at the side between it and the outer wall, these wandering gra- 

 nules can, with certain illumination, be seen like darkish specks moving 

 about, as it were on the surface of the endochrome. They are, doubt- 

 less, identical in nature with the similar active granules in Closterium, 

 Penium, &c. I have not been able to detect any appearance indicative 

 of the occurrence of a circulation, except it may possibly be inferred 

 from the up-and-down movement of these errant granules. But then, 

 when the cell is broken by force these active granules appear to be more 

 numerous, apparently arising from similar granules becoming disengaged 

 by the pressure from the mass of endochrome, and themselves setting-up 

 a movement in the surrounding water, of the same quivering, agitated 

 character (Fig. 4). Those who have seen the " molecular" movement of the 

 granules of the fo villa of pollen will, to my mind, have abetter idea than 

 I could convey of the appearance presented by these moving granules 

 when pressed-out, only they are not so numerous. Perhaps there may 

 be a current within the cell, and that the fluid contents between the 

 mass of endochrome and the margin of the cell may be of too great tenuity 

 to enable it to be detected ; at all events, I have not seen any of these 

 free granules carried directly and steadily onwards, similarly to what 

 occurs in other vegetable cells. I apprehend, however, that the curious 



