ffuiii the Cell-contents of the Characeae. 7 



and ill the interuodc, presenting itself in a mass or branched 

 organized Ibrm, more particularly at those ])arts of the latter 

 which have become ruptured. This also disappears after a few 

 days, and a thorough dissolution of the internode and its original 

 contents seems thus to be completed. 



We have now then seen that a breaking up or displacement of 

 the green layer, a grouping of its green disks, the investment of 

 the groups with a mucus-covering, their com])lete separation, 

 their endowment with a certain amount of polymorphism and 

 locomotion, the turning brown of the chlorophyll, and the passage 

 of the investing mucus into a globular transparent cell, precede 

 the evolution of the gonidial substance and its subsequent self- 

 division into gouidia ; let us now see if there be anything else 

 within the gonidial cell during the time this process is going on. 



It will be remembered, tjiat a great number of discoidal 

 bodies exist in the mucus-layer of the internode, and that many 

 of these are loose, while others are iixed singly in the wall of a 

 transparent vesicle ; now (apparently under an arrest of develop- 

 ment), a gonidial cell frequently presents itself, in which a single 

 disk, with or without its vesicles, precisely similar to one of 

 these, is seen within or to one side of the brown chlorophyll, 

 surrounded by a shrivelled, crenulatcd membrane, appearing, 

 from its irregular mulberry-like surface, want of motion, dingy 

 colour, and absence of refractive granules, as if it were the re- 

 mains of the gonidial substance which had perished from some 

 cause or other just before it began to separate into gouidia. 

 Moreover, in many of the disks, the nucleus is not only seen to 

 be separated from its capsule by an annular interspace, but its 

 granules have become larger and more distinct, and an irre- 

 gular cavity like a contracted vesicle appears to exist in its cen- 

 tre. ^Vhen the circular disk is enclosed within the brown matter, 

 it may be rendered more evident by the addition of alcohol, 

 which extracts the colouring matter completely, while the appli- 

 cation of iodine deepens the colour of the brown matter, and 

 gives a dark brown tint only to the nucleus of the disk. 



That the gonidial cells should contain a nucleus within the 

 brown matter is easily conceived, for on truncating a young in- 

 ternode, sometimes, in the way which I have mentioned, parti- 

 cularly where the green layer is soft and previously disturbed, 

 the whole of the contents rush out together, and all the vesicles, 

 both large and small, become surrounded with green disks, 

 which, under these circumstances, present a similar appearance 

 to that which is witnessed in the internode when the green layer 

 has been bi*ol<en up and its green disks separated into groups, 

 preparatory to the development of the gonidia. 



