PSILOTUM. 



493 



These bodies which when compound, I take to be the enlarged state of 

 the preceding, when distinct, present almost always a hyaline membrane, 

 always a nucleus, occasionally a nucellus, and rarely traces of subsequent 

 sporula. 



The want of the membrane is to be explained by the escape of the 

 nucleus before the separation of the cells composing the masses. 



But what are the granules, which are of all sizes. They generally 

 though not always appear outside the compound sacs. 



Iodine shews that the nuclei which is contained in the compound cells 

 have their own hyaline membrane. According to the condensation of the 

 nucleus, is the development or distinctness of the hyaline envelope. Thus 

 in those in which the central body consist of a grumous disc, enveloping a 

 nucleus, it is some times scarcely, or not all distinguishable, as if the en- 

 velope were formed from circumferential grume. 



Also, in the larger bodies which have separated from the component 

 cells, the marking-out of the spores is evident, even while they appear 

 confined in the compound cells ; the young sporula also becoming deve- 

 loped, in large cellular bodies, in which there is no condensed nucleus. 

 Only two nuclei in one instance appeared grooved out at the back, 

 but these are rare, the bulk consists of cells escaped, or contained in 

 compound cells. 



XIV. In this (a, 1-16) the secondary parent cells evidently escaped, 

 but it is difficult to be seen although 6, 6, obviously must have a parti- 

 cular disposition, but from seeing through so many, it is lost. 



XV. Intermediate stage of sporule when the central cavity presents 

 papillose incrustations on the formation of young cells, 1-10, in this 

 stage the cavity of each cell is filled with a mass of grume, in which the 

 young sporula are in an infinite number imbedded. Neither original com- 

 pound cells, or the parent cells are now evident, the sporules are closely 

 connected together by grume, they are transparent and indistinct, 

 containing no grume, but as to outline, nearly perfectly formed ; almost 

 always both ends appear to contain a cell, the grume forming a sort of 

 belt across the middle. 



XVI. The young fruit is distinctly trilocular, and the outer coat 

 is marked out : either it is very small, or not much larger than the suf- 

 fulting one. 



The parietal cells are well developed, contain some grume, centre 

 occupied by a mucilage, presenting a grumous separable blistered mass ; 

 the blisters not unlike the parietal cells, but much more grumy and less 

 defined. 



XVII. Very early or immediately antecedent to the foregoing dis- 

 tinct parietal cells, the whole solid, the large cells of the centre being 



