FrNGOUS VEGETATION IN LIVING INSECTS. 



339 



terminal part of tlie cell (Fig. 122, b), and press so niucli against 

 each other that their walls become flattened ; whilst nearer the 

 middle of the same filament (c), we find them retaining their 

 rounded form, and merely lying in contact with each other; and 



FiQ. 122. 



Structure of Ihiterohryvs : — A, growth o{ K attemultuSf from mucous membrane ot the stomach of 

 J^swZws/ B, dilated extremity of primary cell of E. elegans, filled with secondary cells, whiab, near 

 its .termination, become mutually flattened by pressure ; c, tower portion of the same filament, con- 

 taining cells mingled with granules ; s, base of the came filament, containing globules interspersed 

 among granules. 



at the base (d) they lie detached in the midst of the granular 

 protoplasma. In U. spiralis, the primary cells (Fig. 121, b, c) 

 very commonly have secondary and even ternary cells [d) de- 

 veloped at their extremities ; but this is rarely seen in U. attenua- 

 tus (Fig. 122). It may be considered as next to certain that the 

 tubular filaments rupture, when the contained cells have arrived 

 at maturity, and give them exit; and that these cells are de- 

 veloped, under favorable circumstances, into tubular filaments 

 like those from which they sprang ; but the process has not yet 

 been thoroughly made out. This is obviously not the true 

 Generation of the plant, but is analogous to the development of 

 zoospores in Achlya (§ 197). It is not a little curious, moreover, 

 that the Entozoa or parasitic worms infesting the alimentary 

 canal of these animals, should be frequently clothed externally 

 with an abundant growth of such plants ; in one instance Dr. 

 Leidy found an Asearis bearing twenty-three filaments of Entero- 

 hryus "which appeared to cause no inconvenience to the animal, 

 as it moved and wriggled about with all the ordinary activity of 

 the species." The presence of this kind of vegetation seems to 

 be related to the peculiar food of the animals in whose stomachs 

 it is found ; for Dr. Leidy could not discover a trace of these or 

 of any other parasitic plants in the alimentary canal of the carni- 

 vorous Myriapods which he examined; whilst he met with a 

 constant and most extraordinary profusion of vegetation (Fig. 



