Plants, and Part/ienoffenesis. 85 



that "the apex of the archegonium ('separation-cell/ Ahsonde- 

 rungszelle) is applied to the curved branch — the antheridium, 

 and that the membrane of the latter becomes absorbed at the 

 point of contact, and then the cells existing in it, filled with 

 colourless muco-gi*anular matter, discharge themselves into the 



* separation-cell/ Once, indeed, I clearly witnessed (as I have 

 represented in fig. 23 c) that in this process the membrane of the 



* separation-cell ' (archegonium) became thrust inwards, whilst 

 the secreted matter existing in it decreased, to make room for 

 the penetrating cell. 



" Whilst it is easy to make out the whole process of fertiliza- 

 tion, it is as difiicult to answer the question respecting the 

 condition of the membrane of the separation-cell (archegonium) 

 in the natural condition of the plant, without preparation, as that 

 respecting that of the embryo-sac in compound higher plants. 

 I succeeded in making this point clear by allowing the cells found 

 in actual union to dry up, whereby the coloured matters which 

 lined the inner wall of the ' separation-cell * were withdrawn 

 from the extremity which was occupied by the cell that had 

 there penetrated it (Pi. IX. A. fig. 23 6 & fig. 23 c). 



" After the act of impregnation is accomplished, the ' separa- 

 tion-cell ' (the archegonium) reassumes the same appearance as 

 before, except that, by transmitted light, the newly produced 

 cell appears of a brownish colour in the centre. 



" The result of the two different forms of conjugation of the 

 contents of the curved (antheridium) and of the ovate (archego- 

 nium) branch-cell is the formation of a similar product : this 

 is the germ of a young plant, which forthwith, or so soon as 

 the necessary conditions are furnished, developes itself into a 

 simple or very slightly branched cylinder. If the plant, for in- 

 stance, after impregnation has been accomplished, be moistened 

 only just so much as is necessary to prevent its being quite 

 dried up, the germs formed are not developed, its contents lose 

 colour throughout, and at the same time its enveloping mem- 

 brane grows thicker. I have kept such germs under observation 

 for three months together. On the contrai-y, when placed in 

 water, they become green again, and develope into long fibres." 



I have here detailed my observations thus fully, in order that 

 they may be compared with the quotations from them given by 

 Pringsheim, through which various more recent authors, who 

 have not given themselves the trouble to refer to the original 

 statements, have been led into error. Pringsheim, who con- 

 fessedly was unacquainted with the plants examined by me in 

 the colony of Tovar, in Caracas, though he investigated other 

 very similar plants, says, when citing my remarks : — 



" In the first place, the extremities of the mother-spore-cells 



