238 Mr. H. J. Carter on the Organization of Infusoria. 



presented to view, seem to elucidate. Thus the nucleus with its 

 capsule, now surrounded by the nutritive contents enclosed within 

 the sarcode, enlarges and passes from its discoid form (elliptical 

 in the large NitelLa) into a globular one* : meanwhile the former 

 becomes distinctly and uniformly granular ; the granules en- 

 large and become refractive ; they assume, en masse, a spheroidal 

 form enclosed within a cell of their own, and thus become di- 

 stinct from the capsule ; at the same time one or more refractive 

 (oil ?) globules, or a nucleus, may sometimes be seen in the latter. 

 While this is going on, a zone of colourless plasma (?) forms all 

 round the capsule of the nucleus, which thus becomes separated 

 from contact with the now hardened cell-wall or pellicula, as 

 well as from the diaphane and sarcode (fig. 94). The next stage 

 is the bursting of the proper cell, and passage of the granules 

 of the nucleus into its capsule, and from thence into the soft 

 plasmic zone which surrounds it. After this, the plasma assumes 

 a mulberry shape, and divides up into monads, which feed upon 

 the enclosed nutritive matters, and are at length seen in the 

 position of the sarcode and diaphane, now circumscribed by a 

 transparent delicate membrane, the second pellicular cystf. That 

 the refractive granules of the nucleus, and portions of the en- 

 closed nutritive contents, which are coloured brown by the dead 

 chlorophyll, get into the bodies of the monads, cannot be doubted, 

 as such matters are seen in them, and could come from no other 

 source. Frequently, however, cells may be seen, apparently 

 under an arrest of development, in which the plasmic zone has 

 assumed a subtuberculated or mulberry form, and the granules 

 of the nucleus are still in their globular cell within the capsule ; 

 hence it may be inferred that the segmentation of the plasma 

 commences before the granules of the nucleus get into it (fig. 96). 

 Again, in a more advanced but still arrested stage, the capsule 

 of the nucleus is seen to be empty, and its bright granules, in 

 the little pouches or mulberry-shaped excrescences of the plasma, 

 now reduced to a mere membrane by arrest of development 

 (figs. 97, 98). From which it may also be inferred that each 

 pouch, which represents a monad, receives one or more of the 

 granules of the nucleus. Does the tuberculated or mulberry 



* I must infer this, because the nuclei in the large species of Nitella, as 

 well as in Chara verticillata, are all eUiptical. 



t Is this degenerated pellicula and diaphane, or a new cyst, composed of 

 the former only ? I am now inclined to the latter theory, here as well as in 

 Otostoma (Ann. and Mag. Nat. Hist. vol. xvi. p. 108 & xvii. p. 118 respec- 

 tively), and that in Otostoma the ciliated coat is divided up for the new litter, 

 while in the rhizopodous cell of the Characeac the diaphane and secreting 

 organ of the pellicular cysts become effete and pass into dissolution. (See 

 the discussion on this point ante, pp. 117, 118.) 



