464 



BOTANY 



PAKT II 



masses of tissue, which give rise to green aerial thalloid lobes. The archegonia 

 occur at the base of these lobes, the antheridia also on their surface. The Lycopod 

 prothalli have fungal filaments forming a niycorhiza in their peripheral tissue. 



The prothallia are all monoecious. The antheridia are somewhat sunk in the 

 tissue (Fig. 410, C) and enclose numerous spermatozoid mother-cells, in which 



Fig. iW.—Lympod'mm clavatuia. A, Old prothallus. B, Protliallus with young ijlant attached. 

 C, Antheridium in vertical section. D, Sjiermatozoids. E, Young archeguuium, the neck 

 still closed. F, Open archegonium ready for fertilisation. G, Plant bearing cones (J nat. sizi')- 

 H, Sporophyll with an opened sporangium. J, K, Spores from two points of view. L, a young 

 subterranean sporeling still without chlorophyll ; /, foot ; ii", root ; h scale-leaves. (.1-/'" 

 and J., after Beuchmann.) 



small oval spermatozoids, with two cilia attached below the apex, are formed. 

 The archegonia (Fig. 410, E, F) are constructed like those of the Ferns, but have 

 a shorter neck, whose upper cells become disorganised on oi)ening. The number 

 of neck-canal-cells differs in the various species (1, 3, 5, or 6-10). 



The embryo (Fig. 412) remains during its development enclosed in the 

 prothallus. It has a si)herical, in L. coviplanatiim club-shaped and irregular, 

 foot which serves as an absorbent organ for the sporeling. Beneath the foot the 

 young shoot forms ; tlie first leaves are scale-like, and from the basal portion of 



