932 



delicate cilia, of considerable length ; a strong artificial light is re- 

 quired to make them out distinctly, and they are best observed when 

 the rotatory motion of the spiral filament has somewhat abated. 

 About six of such cilia appear on each filament, and after this ceases 

 to move they also gradually become quiescent, and are then so closely 

 applied to it as almost to elude observation : still the movements of the 

 cilia endure longer than those of the filament, and not unfrequently re- 

 commence after having once entirely ceased. Neither when in full 

 motion, nor yet after motion has entirely ceased, can the figure of the 

 spiral filament be clearly made out, and this is owing to two causes : 

 Jirsi, its own convolutions and the movements of its attached cilia ; 

 and secondly, because after its motions cease its figure entirely alters, 

 and it becomes a collapsed amorphous mass. It is, therefore, most 

 essential that a moment for observation be selected when, although 

 mature, it still remains within its cellule, or occupies a good and ex- 

 posed position in the field of view. Under such circumstances it will 

 be seen to exhibit two or three convolutions, the clavate extremity 

 being pressed against the wall of the cellule. It should here be re- 

 marked that the clavate extremity of the filament contains a length- 

 ened vesicle in its interior, and also that the other extremity tapers 

 into a filiform tail, and terminates in a minute knot." 



The author regards the parent cells above described as male 

 organs, or antheridia ; the filaments which they contain as sperma- 

 tozoa, granules of pollen, or as the analogues of pollen-granules : and 

 he forthwith proceeds with a description of the female organs or pis- 

 tillidia, in the following words. 



" In addition to the cells containing the spiral filaments above de- 

 scribed, we find on the under surface of the pro-embryo, and located 

 nearly in its marginal sinus, other bodies of greater magnitude and no 

 less important functions. These are hollow oval bodies, and consist 

 of a papilla composed of ten or twelve cells ; while the first-mentioned 

 [the antheridia] rarely contains more than one. The number of these 

 [pistillidia] is very various, sometimes only three and sometimes as 

 many as eight. They also differ from the preceding [the antheridia] 

 in their mode of origin, and in their structure. That they are not 

 identical with them, is proved by their mode of development." 



Here we must again pause for a moment to invite the reader's 

 earnest attention to what follows, because of all writers on this sub- 

 ject Suminski alone insists on this difference ; Nageli, Schleiden and 

 others maintaining that the supposed pistillidia are merely antheridia 

 in a more advanced stage. Seeing, then, that we are dealing with a 



