from the Cell-contents of the Characese. 107 



and in other vegetable cells, viz. that they first make their 

 appearance in the cavity and substance of the protoplasm ; which 

 latter is Cruger's view*. 



In the small species of Nitella, these irregular bodies were 

 almost as frequently found appended to, or in the walls of, a 

 globular vesicle, in the manner of the circular disk or nucleus 

 itself (fig. 15) ; frequently seen in plurality as well as singly 

 within large globular vesicles in both species of Nitella, im- 

 bedded in their internal mucus ; and it often, though by no 

 means always, appeared to me, that the circular disk or nucleus 

 passed into the irregular body. This seems a not unlikely 

 origin for them, and would explain their situation when ap- 

 pended to a vesicle, loose in the granular mucus, or in plurality 

 in the large vesicles; more particularly, as has before been 

 stated, from these being the only positions in which the circular 

 or elliptical disks (nuclei) do appear. At the same time, many 

 may have had their origin in the mucus itself, just as the 

 starch-grains of the green disk, perhaps in germs, and this would 

 account for the minute ones ; but whatever may be their origin, 

 or whether they be a development of Nitella on the globular 

 vesicles, they form part of the contents of the internode, and 

 disappear in the course of the passage of the cell-contents into 

 the so-called '' gonidial cells,'' and the subsequent development 

 of the monads. 



With vesicles so nearly allied to Amoeba and Spongilla, it 

 also seems not improbable that they should take in substances 

 of nutrition after a similar manner ; that is, apparently through 

 their cell-wall ; and although in some cases the irregular bodies 

 may be developed in the nuclei of daughter- vesicles which have 

 not left the parent, yet in others they may have been taken in 

 by vesicles in the way to which I have alluded, viz. for the sake 

 of food. Hence we frequently see one imbedded in the internal 

 granuliferous mucus of a vesicle, and not unfrequently under- 

 going, to a certain extent, that rotatory motion which is pre- 

 sented by portions of food just introduced into the abdominal 

 mucus of Vorticella, Paramecium aurelia, &c. But perhaps the 

 most remarkable instance of this occurs with the green disks, 

 more or less of which become displaced and insulated when the 

 end of the internode is truncated, and thus appear to be caught 

 up by the globular vesicles immediately the two come into 

 contact (fig. 17). Donne first called attention to this, terming 

 the globular vesicles "grosses gouttes huileuses ou albumi- 

 neuses,'' and his observation was confirmed by Dutrochetf. The 



* Ann. and Mag. Nat. Hist. vol. xv. p. 317- See also Mohl's papers 

 translated by Henfrey, with observations by the latter, idem, pp. 321-416. 

 t Ann. des Sc. Nat. Bot. vol. x. p. 348, 1838. 



