264 



THE MICROSCOPE AND ITS REVELATIONS. 



300 diameters '(Fig. 156, A, B). By careful focussing, the flow may be 

 seen in broad streams over the whole surface of the endochrome; and 

 these streams detach and carry with them, from time to time, little oval 

 or globular bodies (A, #), which are put-forth from it, and are carried by 

 the course of the flow to the transparent spaces at the extremities, where 

 they join a crowd of similar bodies. In each of these spaces (B), a proto- 

 plasmic flow proceeds from the somewhat abrupt termination of the en- 

 dochrome, towards the obtuse end of the cell (as indicated by the interior 



arrows); and the globules it 

 contains are kept in a sort 

 of twisting movement on the 

 inner side (a) of the primor- 

 dial utricle. Other currents 

 are seen apparently external 

 to it, which form three or 

 four distinct courses of glob- 

 ules, passing towards and 

 away-from c (as indicated 

 by the outer arrows), where 

 they seem to encounter a 

 fluid jetted towards them as 

 if through an aperture in 

 the primordial utricle at the 

 apex of the chamber; and 



Cyclosis in Closterium lunula:x, cell showing central here Some Communication 



separation at a, in which the large globules, 6, are not hpfwPPn fU p in nor and fho 



seen;-B, one extremity enlarged, showing the movement Between til 6 iniiei and tne 



of globules in the colorless space ;c, external jet produced outer Currents appears to 



by pressure on the cell, probably through an opening in the i i i i A fi 



cellulose envelope ;-D, cell in a state of self-division! take place. 1 Another CUH- 



ous movement is often to be 



witnessed in the interior of the cells of members of this family, especially 

 the various species of Cosmarium, which has been described as ' the swarm- 

 ing of the granules/ from the extraordinary resemblance which the mass 

 of particles of endochrome in active vibratory motion bears to a swarm 

 of bees. This motion continues for some time after the particles have 

 been expelled by pressure from the interior of the cell; and it does not 

 seem to depend (like that of true ( zoospores ') upon the action of cilia or 

 flagella, but rather to be a more active form of the molecular movement 

 common to other minute particles freely suspended in fluid ( 155). It 

 has been supposed that the 'swarming' is related to the production of 

 zoospores; but for this idea there does not seem any adequate founda- 

 tion. 



1 See Lord S. G. Osborne's communications to the " Quart. Journ. of Microsc. 

 Sci., Vol. ii. (1854), p. 234, and Vol. iii. (1855), p. 54. Although the movement is 

 an unquestionable fact, yet there can be no hesitation in regarding the appear- 

 ance of ciliary action described by that observer as an optical illusion; as was 

 early pointed out by Mr. Wenham in the same Journal, Vol. iv., 1856, p. 158. 

 The character of this movement has been described by a recent observer (Mr. A. 

 W. Wills) as one of ebb and flow, alternately towards and from the ends, in deli- 

 cate longitudinal bands or streams; its direction in any one band being usually 

 reversed every few seconds; while in different bands the flow may be in opposite 

 directions at the same time. The clear spaces at the ends of the cell he affirms to 

 be contractile vesicles; and these (he says) can be seen under a l-4th or l-6th inch 

 objective to be undergoing incessant though slight changes in form, with which 

 the flow of the currents can be distinctly connected. (See " Midland Naturalist," 

 1880, p. 187, quoted in "Journ. of Roy. Microsc. Soc.," Vol. iii. (1880), p. 845. 



2 See Archer in " Quart. Journ. of Microsc. Sci.," Vol. viii. (1860), p. 215. 



