106 Mr. H. J. Carter on the Development of Gonidia 



from their points of attachment. It is perhaps more to the 

 breaking of these than to the " bursting of the vesicles '' men- 

 tioned (p. 19), that the "jerking" movements seen every now 

 and then in this mucus are to be attributed ; at the same time, 

 the severation of these threads thus uniting the masses of mucus 

 may still be a vital act. 



The "irregularly shaped bodies" (fig. 11), which are agari- 

 ciform in the mucus of the large Nitella and Char a verticUlata 

 (figs. 12, 13), next claim our attention. They are of an opake, 

 yellowish colour, and bear a strong resemblance to starch as well 

 as to fixed oil. It is stated (p. 4) that iodine only turns them 

 of a " deep brown amber colour ;" but since that, I have fre- 

 quently found it produce in some a deep claret, almost amount- 

 ing to purple tint, with portions here and there which were 

 quite blue. When pressed however, under these circumstances, 

 between two pieces of glass, part of their substance has, in ad- 

 dition, assumed a fatty consistence, of a brown amber colour. 

 What are these bodies then ; and whether do they belong to the 

 globular vesicles or to the mucus of Nitella, or are they deve- 

 loped in both ; and what is their origin ? These are questions 

 for our consideration which we shall now pursue. From the 

 apparently promiscuous formation of starch and fixed oil in the 

 nucule of Nitella, and from the formation of starch-grains, and, 

 probably as often, fixed oil-globules in the protoplasm of the 

 " green disk," it does not appear unreasonable to conceive that 

 similar formations may take place in the mucus-layer (which is 

 also the protoplasm) of the internode. But 1 have lately found 

 that starch is plentifully developed in Spongilla towards the end 

 of the season, when it is about to be left uncovered by the water, 

 and that not only are large starch-grains to be observed, appa- 

 rently in nothing but the intercellular substance, but that many 

 of the cells also exhibit traces of starch among their greenish 

 granular contents ; and some spherical cells appear to contain 

 nothing else but a translucent amyliferous fluid ; while there is 

 no trace of starch to be found in any part of the capsule or its 

 contents, nor in the newly developed Spongilla. With organisms 

 then thus far alike in their products as Nitella and Spongilla^ 

 and the presence of an organism so much like Spongilla in 

 the internode of the former, how to decide which produces 

 these partly amyloid, partly fatty, agariciform bodies that 

 abound in the mucus of Nitella, is a question which had better 

 be postponed until we come to the development of the latter. 

 In the meanwhile, with reference to their origination, I can 

 state no more than I have done with respect to the origin of the 

 starch-grains in the green disks, and the starch-grains and oil- 

 globules which occur together promiscuously in the Diatomacese 



