XIV L YCOPODINE^E 479 



interesting little plant has been carcfull}- investigated by 

 Bower ^ and Bertrand," and the former regards it as the most 

 primitive in structure of all the living Pteridophytes. Unfor- 

 tunately the gametophyte is almost entirely unknown," but the 

 structure and development of the sporophytc have been carefully 

 studied by the above writers. 



The sporophyte resembles in an extraordinary degree the 

 young sporophyte of Lycopodiuiii, especially L. cer7imiin. It 

 grows from a small tubercle (protocorm), which is regarded as 

 homologous with the same structure in the embryo of Lyco- 

 podiicm. This protocorm in small plants produces only sterile 

 leaves — from four to seven — and a small number of roots, often 

 only a single one. In more vigorous plants a smaller number 

 of sterile leaves is formed, but the apex of the protocorm grows 

 into an elongated axis, bearing a single small strobilus at the 

 apex (Fig. 249, A). The structure of the latter is essentially as 

 in Lycopodiuiii. The roots are produced exogenously, as in 

 the Lycopodiuni embryo, and are in structure much the same. 

 All of the tissues are very simple, and none of the organs show 

 a single apical cell, except possibly the apex of the strobilus, 

 where such a single initial seems to be sometimes present 

 (Fig, 249, B, i). At the end of the growing season a new 

 protocorm is formed. This arises directly from the apex of 

 the old one, where no strobilus is developed, but in the latter 

 case grows out upon a sort of peduncle from near the base of 

 one of the leaves. The development of the sporangia is essenti- 

 ally the same as in L. selago (Fig. 249, B). 



The anatomy of the vegetative organs has been carefully 

 studied by Bertrand,"* and corresponds closely to that of Lyco- 

 podiwn, but the tissues arc simpler. In the axis which bears 

 the strobilus there are about six xylem masses arranged in a 

 circle, but there is no definite endodermis limiting the central 

 cylinder. The root-bundle is diarch. 



Bertrand ^ states that M. L. Crie found that the spores 

 germinated readily, and produced a colourless prothallium like 

 that of the Ophioglosseae, both in form and in the structure of 

 the sexual organs, but that the spermatozoids are biciliate. 



1 Bower (5). - Bertrand (3). 



^ The observations of Crie, quoted by Bertrand, were not accessible to the 

 writer. 



* Bertrand (3). ■' Bertrand, I.e. No. 34, pp. 221, 222. 



