57 



to the foui* united sporules could not be seen. On the surface of each of these sporulcs 

 are three short lines, which radiate from the insertion of the stalk." — 489. 



After a time the mother-cell is ruptured, the sporules separate from 

 each other at the centre where the stalks meet, so that each is at first 

 furnished with a short tail, which soon disappears. These sporules 

 at length become perfectly opaque and white, by the gi-adual deposi- 

 tion of matter on the outer surface, and then they contain a little gru- 

 mous matter, having previously been quite empty. The mother-cell 

 entirely disappears, but the author is "inclined to think that a portion 

 of it becomes attached to the surface of each of the sporules, of which 

 there are about forty in each sac." After arriving at this stage no fur- 

 ther change appears to take place. 



Up to the time of their becoming pellucid and receding from each 

 other, the sporules in the lower part of the involucrum are developed 

 in precisely the same manner as those in the upper, but here the ana- 

 logy ceases. At this period, instead of the mother-cell being broken 

 up and disappearing while the sporules remain entire, the greater 

 number of the sporules themselves are ruptured and the unchanged 

 mother-cell continues to envelope them. 



" The shrivelled remains of the ruptured sporules continue to be attached to each 

 other by their stalks, and the mother-cell remains perfect ; in short no further change 

 takes place, for they may be found in this state in the same sac with the ripe spo- 

 rules. The two or three unruptured sporules which are single in each union * * 

 enlarge, each struggling for the mastery, and it is not long before one prevails, the 

 smaller ones rupturing and passing into the same state as those first ruptured. The 

 sole remaining sporule now enlarges rapidly, assumes a pyriform shape, and the mo- 

 ther-cell gradually recedes from it by a still more rapid enlargement, except around 

 the narrow extremity to which the three ruptured sporules which form the union are 

 attached, where the mother-cell has contracted an adhesion. It appears that this dila- 

 tation of the mother-cell is caused by a secretion of fluid between it and the sporule, 

 for if the cell be punctured the fluid will escape, and the cell return by its elasticity to 

 the same dimensions as the sporule." — p. 490. 



This stage is marked by the disappearance of the three ruptured 

 sporules, which till now had remained attached to the growing one : 

 the author conjectures that they may escape by an aperture in the mo- 

 ther-cell, which is visible at a later period. A deposition of opaque 

 matter on the mother-cell now takes place, and forms the outer coat of 

 the sporule ; and — 



" When the outer coat is completely formed, the mother-cell or middle coat ceases 

 to enlarge, whilst the inner sac or true sporule continues its growth until it is checked 

 by coming in contact with the inner surface of the mother-cell, to which, in its mature 

 state, it is firmly adherent. The sporule is at first perfectly pellucid and deficient of 



