INTRODUCTION TO CRYPTOGAMIC BOTANY. 165 



more nearly allied to Horraospora. The singularity consists 

 in the repeated division of the endochrome, till we have a tube 

 constricted at regular intervals, each division containing a 

 glceocapsoid mass, so as to present some similarity to a Seiro- 

 siphon. Whatever its true affinities may be, it is too singular 

 to allow of its being passed without notice. 



1 40. It may be well to add a few words here on Oiwhydiwni 

 versatile, Ehrb., the component animals in tlie mass of which 

 have so great a resemblance to the zoospores of some Algas. 

 The masses are an inch or more in diameter, and resemble 

 closely those of Rivularia j^fu^iiformis. The individual 

 animals are all supported on delicate hyaline threads, which 

 are altogether neglected in Ehrenberg's figure. They have 

 two sets of cilia at the apex, much after the manner of the 

 zoospores of (Edogoniurti, but the whole of the apex is re- 

 tractile at will, insomuch that the ciliatory motion is often 

 discernible in the centre. This would not take place without 

 muscles. The contents of the cells closely resemble the chlo- 

 rophyll of Vaucheria, and deserve a comparative study. I 

 do not find that the cell wall is blue with iodine and sulphuric 

 acid. The green granules, under the same treatment, imdergo 

 the same changes as those of Confervce or Vaucheria. In 

 Poggendorfs Annalen der Phys. and Chem., 1855, there is a 

 notice by Salm-Horstmar, on the green matter of Infusoria. 

 It is, however, uncertain what species are meant. If Diato- 

 macece, the case is not one in point. According to him, it is 

 not of the nature of wax, and no true chlorophyll. See Bot. 

 Zeit, 1855, p. 596. 



141. Before I quit the subject of Glilorosper7)is altogether, I 

 shall add a few words respecting the variations to which they 

 are subject. By variations, I do not mean the changes which 

 may take place in different stages of growth, but those changes 

 which are dependent on other causes, whether constitutional 

 or external. When a Desmidiad is propagated by a spore, 

 the spores are so totally different in form and sculpture, that 

 the plants first formed by them must be very different 

 from ordinary individuals, as the growth from spores and 

 cells is conducted on the same princii)le. The first plant will 



