FERTILIZATION OR FECUNDATION. 237 



dioica, and a plant called Coelebogyne, perfect seeds have been pro- 

 duced without the influence of any substance equivalent to pollen ; but 

 these statements have not as yet been confirmed. On the contrary, 

 in Phanerogamus or flowering plants, all experiments lead to the con- 

 clusion that there are distinct sexual organs. 



492. In Cryptogamous or flowerless plants, considerable doubts have 

 been entertained as to the existence of such organs. There seem 

 to be in this case cells of different kinds, which require to be brought 

 into contact in order that spores (which are equivalent to seeds) may 

 be produced. These reproductive cells are of two kinds, and they 

 are situated either together or apart, on the same or on different 

 individuals. One of these is the AnthericUum, a cellular body contain- 

 ing granular matter, and Phytozoa (tpvTo*, a plant, and ioY, living), 

 or minute bodies which exhibit movements ; the other is the Pistilli- 

 dium or Archegonium (n%,'/j, beginning, and yovo;, offspring), containing 

 spores which germinate, and which are some- 

 times provided with cilia (figs. 431 434), 



so as to become Zoospores (00;, living, and 

 (j~oox, a seed or spore), or moving spores. The 

 contact of the Antheridium and PistiUidium 

 is by many considered as necessary for the fer- 

 tilization of the spore. In other cases, as in 

 Conferva? and Diatomacese, there is a union of 

 the cells of the plant by conjugation, so as to 

 produce germinating bodies. In these cases, 

 the contents of one cell pass, by the formation 

 of a tube, into the other. In Zygnema, this 

 conjugation gives rise to germinating bodies in 

 the interior of one of the cells of the plant ; in Diatomaceas, on the 

 outide of the cells. 



493. The union of two lands of endochrome (f^o, within, and ^^*, 

 colour), or of two kinds of coloured particles, appears in these plants 

 to give rise to the sporangium or spore-case, and the spore. Some- 

 times the two kinds of endochrome are in separate plants, as already 

 noticed, and then conjugation unites them, and causes a mixture of the 

 endochrome; while in Meloseira, &c., the different kinds are apparently 

 situated in different parts of the same cell, and movements take place 

 towards the centre, by which their union is effected and a spore pro- 

 duced. In Ferns, Mosses, &c., there have been detected separate cel- 

 lular bodies, the union of which is considered necessary for the perfec- 

 tion of the spores. In many Cryptogamic plants, besides this kind of 



Fig. 431 434. Spores of different fresh-water Alga. 

 Fig. 431. Spores of a Conferva, with two vibratile cilia. 

 Fig. 432. Spore of a Quetophora. with four cilia. 

 Fig. 433. Spore of a Prolifera, with a circle of cilia. 

 Fig. 434. Spore of a Vaucheria, covered with cilia. 



