LYCOPODIACEyE 



55 



A 



of small leaf-like lobes, beneath which are the archegones and antherids 

 on the same prothallium, and buried in its tissue. Each antherid arises 

 from a single superficial cell, which divides by a transverse septum into 

 an outer stigmatic cell, subsequently splitting up into three, and a basal 

 cell in which the antherozoids are formed. The archegone has a very 

 short neck, consisting of three rows of cells. While the prothallium dis- 

 plays greater differentiation than is the case elsewhere in Vascular 

 Cryptogams, the embryo or young 

 sporophyte is, on the contrary, of 

 very simple structure, and entirely 

 parenchymatous. A cotyledon is 

 formed at one end, but there is no 

 primary root, or other differentiation 

 of organs. In L. Phlegmaria (L.) 

 the prothallium is cylindrical, with- 

 out chlorophyll, and branches freely. 

 The rhizoids proceed from a super- 



B 



C 



Fig. 36. — Prothallium of Z.. Phlegmaria L. Bifurcate 

 branch bearing antherids, a, and paraphyses, p 

 ( X 90). (After Treub.) 



Fig. 37. — Lycopoduim clavatiim L. 



A , sporangiferous branch (natural size) ; 



B, sporange and subtending leaf (greatly 

 magnified) ; C, spore, showing lines of 

 fissure (still more magnified). 



ficial layer, which also branches laterally, by which means fresh 

 prothallia are constantly being formed without any production of sexual 

 organs. The archegones and antherids are borne on the upper surface 

 of the prothallium, and are always accompanied h^^ paraphyses^ barren 

 tubular cells of rare occurrence among Vascular Cryptogams. The 



