from the Cell-contents of the Characere. Ill 



monad dcvclopecl from it, in the cells of the filaments producing 

 the antherozoids of the globule. 



We have now to examine the development of the first few cells 

 of the new plant successively, in order that we may trace the 

 development of the mueus-laycr. 



In the Characcnc, as in Cladoj)hora, but not as in Spirogyra, 

 the coat innnediately covering the grunious contents of the spore 

 in one case and the nucule in the other, appear to be prolonged 

 into the cell-wall of the new plant. I infer this from the cell- 

 wall of the first internode being so firmly attached to the inner 

 coat of the nucule that it cannot be separated from it without 

 rupture, since the black colour of the middle coat prevents our 

 seeing how the continuation is effected after the manner of 

 Cladophora, where the old cell and the spore-capsule are equally 

 transparent. By a prolongation of the internal coat into the 

 new cell-wall, I mean that the former becomes soldered to the 

 latter, as the latter is secreted or formed by the protoplasm of 

 the nucule. 



Having come to this conclusion, we will now follow the ex- 

 tension of the new plant to the sixth cell, exclusive of the 

 cavity of the nucule. At this period we shall find it about 

 one-fiftieth of an inch in length, and the circulation or full 

 development of the mucus-layer only established in the cell next 

 the nucule, which we shall designate the first, and so on to the 

 terminal one, which will be the sixth. 



Beginning then from the sixth, or youngest cell, and tracing 

 the development backwards, or towards the nucule, we shall find 

 the following appearances : — 



In the terminal or sixth cell, which is not fully formed, 

 nothing is seen within the cell-wall but a mass of small spherical 

 hyaline vesicles of different sizes, and the barely perceptible 

 rudiments of the green disks (fig. 36). In the fifth the number 

 of vesicles are diminished, by some being larger than the rest, 

 especially two in the centre, and the rudiments of the green 

 disks more distinct. In the fourth the two large vesicles 

 (spaces ?) have united into one, and many of the smaller ones 

 have broken down into, or have been replaced by mucus ; the 

 rudiments of the green disks are more evident. In the third 

 the same changes are seen, but still more advanced ; while in 

 the second the central space is much larger, though irregular in 

 form ; the mucus increased in quantity, apparently at the ex- 

 pense of the hyaline vesicles, which are now very few ; and the 

 whole beginning to move gradually round the cell. In the first 

 the circulation is established ; no hyaline vesicles are seen in the 

 mucus, though already it presents some of the '' irregularly 

 shaped bodies," and the green disks are found. 



