384 



BOTAJYT. 



Order Xiycopodiaceee. — The prothallium is known only in one case, 

 viz., Lycopodmm annotinum. It was discovered underground by 

 Fankliauser in 1873, who described it* as a yellowish white, irreg- 

 ularly lobed body, sparingly furnished on its under surface with small 

 root-hairs (Fig. 274,^). In its upper surface the prothallium bears 



antheridia, which are 

 ^ ^-^ *^ deeply sunken in its tis- 



sue {an. Fig. 274, A); 

 the spermatozoids, which 

 are numerous, are stout 

 and slightly twisted. 

 The archegonia were 

 only seen after the young 

 plants had grown con- 

 siderably (Fig. 274, B) ; 

 they are likewise devel- 

 oped upon the upper 

 surface of the prothal. 

 Hum, and appear to bear 

 a considerable resem- 

 blance to those of the 

 Ophioglos^acecB. 



The young plant which 

 results from the growth 

 of the fertilized germ- 

 cell is quite simple, but 

 it soon takes on the form 

 of the mature plant. 

 The leaves are crowded 

 in Lycopodium, but are 

 less so in the other gen- 

 era. In many species 



L ;" e, e', two embryos, the larger one with the sporangia are borne 



r projecting into the neck of the ai'Chego- ■ xi •> f ^■• 



3 left of the larger embryo is a young ar- ^" ^^° axiis 01 me or- 



Fig. 27H — r.crmination of the spores of SdagineUa. 

 1, longitudinal section of a niacrospore nf S. Marten- 

 ■ above the line d is the prothallium, below it the 



bryo 18 a young 8 

 i also shown. 2, 



*' endosperm 

 Its suspeneor 



nium ; at the left of the larg( 

 chegonium ; several root-hairs are 

 young archegonium of the same species.'not yet open, 

 3, an archegonium of the same species, with the germ- 

 cell fertilized and dividi d info iwo. .4, a microspore 

 of S. caulescenSy rendered frant-parent, showing the di- 

 vision of the contents into the primordial cells; the 

 small lower cell is the rudimentary prothallium. D, 

 later stage of the same, showing the^arge antheridium 

 filled with sperm-cells ; v. the rudimentary prothal- 

 lium. All magrrifled.— After Pfefler. 



dinary leaves, but in 

 others the leaves which 

 bear sporangia are col- 

 lected into cone-like or 

 spike - like structures, 

 which terminate certain 

 branches (Fig. 275). The 

 which are short-stalked 



sporangia are more or less globose bodies 



or sessile ; they contain large numbers of small spores, which escape 



by an apical slit in the sporangium. 



* J. Fankhauser : " Ueber den Vorkeim von Lycopodium," in Botan- 

 ische Zeitung, 1873, No. 1. 



