88 CHARACEiE. 



ports the stalk of the seed-vessel ; and thirdly and fourthly, 

 two other cells, which lie on each side of the cell, supporting 

 the stalk of the globule. " In ordinary tubes or cells," Mr. Yar- 

 ley writes, " there are green vesicles regularly arranged on 

 the thin membrane which lines them, and the circulating: fluid 

 appears thickened by innumerable particles, a little denser, or 

 not quite fluid, and with scarcely any colour. But in these 

 peculiar cells there are generally very few stationary green 

 vesicles, except about the angles formed by the adhesion of 

 other cells. The fluid within is very clear and limpid, with 

 many very equally sized green granules floating in it. Those 

 that are still, and those that are moving, appear to be the 

 same ; and some are seen to stop, and some stationary ones 

 are seen to break loose and go on : they are rather larger 

 than the orderly arranged green vesicles of other cells ; but 

 being loose, and the cells so glossy, they are seen very bright 

 and distinct. This is not all ; for they circulate round the 

 cells very quickly and freely, undergoing some extraordinary 

 influence; for they knock against one another, aj)j)ear to 

 stick at some places, or as if they squeezed by, and then rush 

 on quicker : many, as they come near particular parts of the 

 cells, spin round most rapidly as they go on, different particles 

 turning in opposite directions ; and others only catch a slight 

 impulse to spin, suddenly turning round and back again, and 

 go on without spinning ; others, near the centre of rotation, 

 go round together, then start into a quick whirl, then vary 

 or slacken, and again start into a furious whirl, showing 

 considerable fluctuations in their motion ; and in the larger 

 rounds they appear to receive some impulse whenever they 

 touch that part of the surface which joins the arm, as though 

 they were slightly electrified." These motions precisely re- 

 semble those of the zoospores, and are doubtless voluntary, 

 performed, as in their case, by means of vibratile organs or 

 cilia. 



We will now describe the globule itself: this, as has 

 already been observed, is spherical, with a light red nucleus, 

 the coating being made up of about eight deeply indented 

 triangular segments. (See plate LXi. fig. 4.) These con- 



