THE HIGHER CRYPTOGAMIA. 163 



sometimes exhibit slow expansions and contractions similar 

 to those of many of the inferior animals ; for instance, the 

 smaller Ameeba3. It is especially in such cases that the 

 delicate mucilaginous membrane which encloses the cell- 

 contents may be most clearly observed. 



By continued absorption of water the primordial utricle 

 becomes pressed laterally against the cell-wall ; the granules 

 which float in its fluid contents exhibit active molecular 

 motion. Ultimately, the cell-membrane is ruptured, usually 

 at the spot where the primordial utricle is in contact 

 with it, and the latter escapes through the fissure. It 

 then usually bursts, but occasionally I have seen the 

 primordial utricle glide out through the fissure of the cell 

 in the form of a closed, tightly stretched globular vesicle 

 (PI. XXI, fig. 8). The internal granules (consisting of 

 starch and a substance rendered brown by iodine), conti- 

 nued their active molecular motion, which stopped sud- 

 denly, when a drop of diluted watery tincture of iodine 

 was applied. The membrane of the primordial utricle 

 shrivelled up to some extent, and assumed a yellowish- 

 brown colour (PI. XXI, fig. 8, b). 



In one instance I observed a very peculiar state of the 

 primordial utricle. As I brought the object under the 

 microscope, it floated freely in the form of a globular 

 vesicle in the interior of the swollen cell. Afterwards it 

 approached the cell-wall, and attached itself to one of the 

 sides, assuming the form of a slightly compressed sac 

 (PI. XXII, fig. 1.) Half the cell-cavity remained empty, 

 or at least contained only water. The primordial utricle 

 gliding up to the inner wall of the cell commenced a slow 

 rotatory motion. 



It has been already mentioned that the walls of the 

 secondary mother-cells swell rapidly until they burst. If 

 a section of a capsule containing fully formed tertiary 

 mother-cells enclosed within secondary mother-cells is 

 placed under water, it often happens that all the spore- 

 mother-cells escape out of the ruptured secondary mother- 

 cells, and become dispersed in the water upon the slide. 

 At this stage of development of the capsule the fluid con- 

 tents even of the cells of the outer capsule-wall attract 



