On the development of the Sporce of Anthoceros laevis. 87 



the middle of the cellule, where they reunite. That which 

 weighs at least some thing in favour of this theory is," that 

 at the period when these lines appear for the first time (fig. 

 23), the filaments of fibroso-mucilaginous substance which 

 pass from one granular cellule to another, exist yet in all 

 their integrity, which proves that in the interior there can- 

 not yet be any septa formed. 



But a point which merits also to be mentioned, is, that in 

 consequence of the action of water on the mother-cellules 

 those lines can be made to disappear again ; thus it appears 

 to indicate that they were only formed by a very small ele- 

 vation towards the interior, and it is this elevation which ap- 

 pears to be changed in consequence of the hygroscopic en- 

 largement which the membrane of the mother-cellule has 

 undergone. 



This state which consists in lines found on the wall of the 

 simple cellule, soon passes, because in the greater number of 

 cases in which the division of the cellular wall on such like 

 surfaces is visible, we find that the septa also are already 

 completely developed. Those septa, as it results already 

 from their relative position, have a triangular form. 



Two of their faces are plain, and the third, that which 

 is turned towards the exterior, is convex ; these are very thin, 

 and are formed, like the mother-cellules, of a semigelatinous 

 substance, which is not affected by iodine. 



The nucleus of the mother-cellule, difficult to discover 

 before the division, exhibits now no trace after the division 

 is produced ; it would appear to have been entirely absorbed 

 at this period. 



Each of the four divisions of the mother-cellule formed 

 by the septa, contains one of the four granular cellules 

 (figs. 24, 26). These latter do not change at first, because 

 they contain yet a great number of amylaceous grains (fig. 

 24, 25), and become slightly tinged of a green colour 

 from the influence of iodine ; but soon in the greater num- 



