90 On the development of the Sporce of Anthoceros Icevis. 



ing, and the mother-cellules in which they were contained, 

 and which now have assumed a yellowish tint, evacuated, 

 and enveloped by a little mucilage become placed against 

 the wall of the sporae (fig. 28). These mutations of the 

 granular cellules are produced sometimes sooner and some- 

 times later, or it may happen while the membrane of the 

 spora is still of a clear yellow and very transparent, 

 there yet exists a considerable accumulation of granules 

 when even this membrane is of a yellowish brown and 

 little transparent. In the end the little cellule seems al- 

 ways to become resolved, for in the ripe spora? we find 

 only a grumous, mucilaginous liquid, mingled with particles 

 of oil. 



I may be permitted to add a few observations on the above 

 exposition of the results obtained by my inquiries on the 

 Anthoceros. 



As to the mother-cellules, those inquiries perfectly con- 

 firm the opinion of M. de Mirbel, that they become divided ; 

 my former opinion, that in the more elevated cryptogamous 

 plants the four sporae become developed by the side of 

 each other in the cavity of the mother-cellule, is therefore 

 decidedly ill founded.* 



On the other hand, I presume that my observations on the 

 contents of the mother-cellules should modify some little the 

 theory proposed by M. de Mirbel, indeed according to this 

 high authority the formation of the sporas should depend 

 more particularly on the mother-cellule, the contents of 

 which are described as a homogenous, mucilaginous, grum- 

 ous liquid, that the raised septa divide mechanically into 

 four parts. This theory is therefore in direct opposition to 

 mine, according to which, the development of the four sporae 



* The open acknowledgment of error, as in the present case, is com- 

 monly the characteristic of distinguished talent. And perhaps more 

 particularly so in natural history than in any other scientific or literary 

 pursuit — Jos. M. 



