8 GEXETIAL HISTORY OF THE INFUSORIA. 



am inclined to believe that this is not so, that this is some ocular deception, 

 and that these ciha, so seen, are within the outer case. It may be that these 

 cilia are on the external surface of the membranous sac, as well as over the 

 endochrome ; more practised observers with higher powers may yet determine 

 that. Of the existence of the cilia throughout the plant there can be no 

 doubt, and no object I have ever seen will bear comparison with this when 



beheld under sunhght It is seldom that I can trace a current up one 



margin, and round the point down the other ; these currents seem to me as 

 the rule to pass from the point, when they reach it, down to the centre of 

 the spot where the cilia are seen terminating the endochrome." 



In a second part of this communication the writer adds : "I have scarcely 

 failed in one attempt to see the circulation and cihaiy motion in the Clos- 

 terium Lunula. I tried today heating a little water, by putting a small bottle 

 in a cup of warm water ; the eifect seemed to retard the circulation, but to 

 make the globules larger. I have traced it over the whole extent of the en- 

 dochrome, but it is best seen at the convex sid.e a short way from the edge. I 

 am more than ever convinced the cyclosis is the waving of attached tongues 

 of cilia. The specimens are capricious in the results they afford ; they show 

 best when the sun has been on the jar for a time, I have watched the move- 

 ments of the globules in Yallisneria, Nifella, &c., and they are to me altogether 

 of a different natiu'e to that in the Closterium^ &c. To my eye there is no 

 real analogy between this circulation and that in the above plants ; but there 

 is much more with the branchial action in the mussel." Mr. Jabez Hogg's 

 supplementary notes to Mr. Osborne's paper represent the whole frond as 

 *' brilliantly glittering with the moving and active cilia ; whilst in the 

 cyclosis numerous zoospores were most actively moving about hj the same 

 agency. When the sunlight falhng on these httle bodies warmed them into 

 life and motion, the rapid undulations produced hj the action of the cilia 

 illuminated the whole frond with a series of most channing and dehcately- 

 coloured prismatic fringes or Newton's rings. The motion and distribution 

 of the cilia must be seen by the aid of the direct sun-rays and parabola ; for 

 although I tried every other mode of illumination, and with Mr. Brooke used 

 Gillett's condenser, yet neither of us noted satisfactorily their situation and 

 distribution until we resorted to the parabola. At the same time the cir- 

 culation may be most accurately obseiTed to take place over the entire 

 surface of the frond. The stream is best seen to be nmning up the external 

 margin, just internal to a row of cilia, with another taking a contrary direc- 

 tion next to the serrated ciliary edge of the endochi'ome ; the whole being 

 restricted to the space between the mass of endochrome and hyahne integument 

 passing above and around the cyclosis, but not entering into it." 



Another wiiter (J. M. S. 1855, p. 84), Mr. Western, adduces an observa- 

 tion which he believes to confirm the presence of ciha in Closterium, and 

 even goes so far as to advance the notion that the circulation in the cells of 

 Chara, and, by analogical reasoning, in those also of other water-plants, 

 originates in cihary movements. In Chara, as in Closterium, he tells us, he 

 observed " precisely the same appearances, the same rapid undulations, to- 

 gether with the same brilliant coruscations." Dr. Wright, whose contribu- 

 tion in the same Journal (1855, p. 171) we have previously quoted, admits 

 the presence of cilia, and starts the extraordinaiy supposition that the circu- 

 lation of the contents of Closterium is carried on through canals or vessels, 

 which he describes as marginal, and that it is independent " of a frequent 

 irregular movement of granules of endochrome more resembhng imperfect 

 cyclosis." 



If our doctrines concerning the physiology of animal and vegetable cells be 



