834 REPRODUCTION OF LYCOPODIACEZ AND EQUISETACE#. 
commence to germinate, nor are the antherozoids produced till 
a nearly equal period has elapsed. In germination, the spore 
(macrospore) produces a very small prothallium (fig. 1156, p), 
on which archegonia (fig. 1157, a) are subsequently developed. 
Each archegonium (fig. 1157, a) consists of an intercellular 
canal leading into a sac below, which contains a single germ or 
embryonal cell. In the microspores one cell only constitutes 
the prothallium ; all the others are mother-cells, which by dividing 
several times produce antherozoids. Fertilisation takes place 
by the ciliated antherozoids contained in the microspores ( fig. 
1155, ¢) passing down the canal of the archegonium and coming 
into contact with the germ-cell. This cell then grows by cell- 
Fig. 1156, Fie. 1157. 
Fic. 1155. 
Fig. 1155. Small spore, or microspore, of a species of Selaginella, bursting 
and discharging small sperm-cells, c,in which antherozoids are con- 
tained. Fig. 1156. Large spore, macrospore, or megaspore, of a spe- 
cies of Selaginella. The outer coat of the spore has been removed to 
show the entire inner coat, with the young prothallium, p, at the upper 
end.— Fig. 1157. Vertical section of a portion of the prothallium of the 
above in a more advanced state, showing the archegonia. a. Arche- 
gonium, in which the pseudo-embryo. e, has been developed from the 
germ-cell 1t contained, by contact with the antherozoids. This embryo, 
by the growth of the suspensor, is forced downwards and imbedded in the 
upper part of the cellular mass of the spore-sac. 
division and forms a pseudo-embryo (fig. 1157, e), and ultimately 
produces a new leafy sporangiferous stem. 
(5) Lycopodiacex or Club-Mosses probably have only one kind 
of spore (microspore), from which is produced a prothallium bear- 
ing antheridia and archegonia : the germ cell of the latter being 
fertilised by the antherozoids which escape from the mature 
antheridia, and producing in turn an adult plant, Very little, 
however, is known for certain about the life-history of the Lyco- 
podiacez (see page 368). 
(6) Equisetacee or Horsetails. And 
(7) Filices or Ferns.—The mode of reproduction of the plants 
of these two orders is essentially the same, and we shall ac- 
cordingly allude to them together. As already fully described 
(see pages 365-368), their leafy structures bear sporangia or cap- 
sules in which the spores are enclosed (jigs. 802-805, and 810-812). 
There is but one kind of spore. 
we eee i 
