THE HIGHER CRYPTOGAMIA. 17 



is certainly of great importance with reference to cell-multi- 

 plication. However, since I made the experiment of using 

 alcohol in the observation, I found in every fruit which was 

 submitted to dissection spove-mother-cells (situated between 

 spore-mother-cells which were yet undivided and others 

 which were already completely divided into four daughter- 

 cells) the inner walls of which were traversed by the rudi- 

 ments of the future septa, in the form of ridges protruding 

 inwards (PL II, fig. 12). By adding water to such a 

 preparation, the imperfect septa are seen to be direct con- 

 tinuations of the innermost layer of the cell-wall, which 

 layer swells up but little in water (PI. Ill, fig. 13). The 

 swelling up of the inner layers of the membrane of the 

 mother-cells has a peculiar appearance in those mother-cells 

 in which very numerous strings of protoplasm pass from 

 the tertiary nuclei to the cell-wall.' The enlarging sub- 

 stance of the membrane does not force these strings in- 

 wards, but shapes them to itself and clings to them (PI. 

 Ill, fig. 15). The swollen substance of the membrane is 

 manifestly less firm than that of the strings of protoplasm.* 

 Nevertheless, the swollen layer of the wall exhibits sharp 

 broken edges when the cell is ruptured by pressure with 

 the covering-glass. It is only after prolonged soaking in 

 water that the substance of the swollen layers becomes dis- 

 integrated ; the middle layers first dissolve, and then the in- 

 nermost ones ; the outermost layer remains behind to the last. 

 After the walls of the special mother-cells have attained 

 a moderate thickness, there is formed in each one of them 

 a single spore, which, from the first moment of its membrane 

 becoming visible, occupies the entire cavity of the mother- 

 cell. In Anthoceros punctatus, the prominences attached to 

 the outer membrane of the spore exactly fill up the dots of 

 the wall of the mother-cell. Irregularities of spore forma- 

 tion occur in both species : occasionally two special-mother- 



* It was probably the observation of similar cases which led Kiitzmg to the 

 erroneous notion that the prolongations of the exosporium were hardened, 

 thread-like prolongations of the protoplasm surrounding each of the nuclei. 

 ('Philos. Bot.,' Lcipz., 1S51, p. 264-.) The error of this view is at once mani- 

 fest, from the fact that the exosporium of Anthoceros presents, at its first 

 appearance, an entirely smooth outer surface. Its protuberances originate at a 

 later period. 



2 



