On the development of the Sporae of Anthoceros leevis. 89 



irregular depressions, it happens commonly that the young 

 sporae manifest on their external surfaces undulated emi- 

 nences and depressions, which only disappear in consequence 

 of ulterior development. 



From the time that the membrane of the sporas becomes 

 developed, the sporae may be separated from each other by 

 pressure (fig. 27) ; when this compression is augmented, the 

 mother-cellule lacerates, and the sporae pass out by the 

 opening formed in this manner. When chance favours us, 

 we can sometimes see the mother-cellule forming thin septa 

 between the sporae. 



The membrane of the sporae is first colourless and smooth > 

 afterwards it becomes finely granular (fig. 28) on the con- 

 vex surface, which is in contiguity with the external wall of 

 the mother cellule ; at the same time it assumes a yellowish 

 tint ; at a still later period, the three surfaces of the pyrami- 

 dal summit become granular (fig. 29), and the angles be- 

 come thickened. 



By compressing the sporae of the Anthoceros between two 

 pieces of glass we cannot prove the duplicity of their mem- 

 brane ; but the presence of an internal membrane is very 

 probable, because of the analogy between these sporae and 

 those of other more perfect cryptogamous plants and mosses. 



The ulterior mutations between this period and the ma- 

 turity of the sporae, are in relation either with the mother 

 cellule, or with the sporae themselves. 



The mother-cellule as soon as the membrane of the 

 sporae become perfectly developed loses its anterior state of 

 hygroscopicity ; in proportion as the sporae augment in vo- 

 lume, and become more and more thickened, the mother 

 cellule becomes thinner and thinner; in fine, when it ap- 

 proaches the period of maturity it becomes entirely ab- 

 sorbed. 



In the sporae themselves the number of the amylaceous 

 grains diminishes, and terminates by completely disappear- 



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