274 THIRD GROUP. VASCULAR CRyPTOGAMS. 



IV. LYCOPODINEAE. 



Under the name Lycopodineae are included the Lycopodieae, Phylloglossum, 

 Psilotum, the Selaginelleae and Isoeteae. The Lycopodineae agree on the whole 

 with the Ophioglosseae, Marattiaceae, and Equisetaceae especially in the mode of 

 development of their sporangia. In habit they are distinguished at once from the 

 Filicineae by the circumstance that in the latter the critical point as regards the 

 morphological characteristics is in the leaves, whereas in the Lycopodineae the leaves 

 are precisely the organs which are most simply formed, and are unimportant in size, 

 with the exception of Isoetes, though they are usually many in number. A feature 

 common to most of the Lycopodineae is the frequent dichotomous branching of the 

 stem and root, though examples of genuine monopodial branching are not wanting. 

 The position of the sporangia varies ; in Lycopodium and Phylloglossum there is a 

 single sporangium on the upper side at the base of the leaf; the position is the same 

 in Isoetes but the sporangium is multilocular. In Selaginella the sporangia are 

 formed singly from the surface of the stem above the leaf; in Psilotum they occur 

 several together and sunk in the extremities of short lateral branchlets. 



A. LYCOPODIACEAE 1 . 



1. HOMOSPOROUS LYCOPODIACEAE (LYCOPODIUM AND 



PHYLLOGLOSSUM). 



The prothallium or sexual generation (pophore, oophyte). The circumstances 

 attending the germination of Lycopodium and Phylloglossum are up to the present 

 time unknown 2 , though many have attempted their cultivation. De Bary is the only 



1 Bischoff, Die kryptogamischen Gewachse, Niirnberg, 1828. Spring, Monographic de la famille 

 des Lycop. (Mem. de 1'Acad. roy. belgique, 1842 and 1849). Cramer, Ueber Z^w/. Selago, in Nageli 

 u. Cramer, Pfl.-phys. Unters. Heft 3, 1855. De Bary, Ueber d. Keimung d. Lye. in Ber. d. naturf. 

 Ges. zu Freib. in Br. 1858, Heft 4. Nageli u. Leitgeb, Ueber d. Wurzeln, in Nageli's Beitr. z. wiss. 

 Bot. Heft 4, 1867. Payer, Bot. cryptogamique, Paris, 1868. Hegelmaier in Bot. Ztg. 1872, No. 45, 

 and 1874, p. 513. Russow, Vergl. Unters. Petersburg, 1872, p. 128. Mettenius, Ueber Phyllo- 

 glossum (Bot. Ztg. 1867). Juranyi, Ueber Psilottim (Bot. Ztg. 1871, p. 180). Fankhauser in Bot. 

 Ztg. 1873, No i. Strasburger in Bot. Ztg. 1873, No. 6. Bruchmann, Ueber Anlage u. Verzwei- 

 gung d. Wurzeln von Lycopodium u. Isoetes (Jen. Zeitschr. f. Naturwissenschaft, viii, p. 522). 

 Goebel, Beitr. etc. II (Bot. Ztg. 1880 and 1881). [Treub, Etudes sur les Lycopodiacees (Ann. d. 

 Jard. Bot. d. Buitenzorg, iv, 1884. Bruchmann, Das Prothallium v. Lycopodium (Bot. Centralbl. 

 xxi, 1885). Thiselton Dyer in Nature, 1885. Bower, on the Development and Morphology of 

 Phylloglossum Drummondii, Part I, Vegetative Organs (Proc. Roy. Soc. xxxviii, 1885). See also 

 the literature mentioned by Solms as quoted on p. 282. 



2 [Bruchmann found in the Thuringer Wald, in Aug. 1884, three prothallia of Lycopodium 

 dnttotittum'said he described them in Bot. Centralblatt, xxi, 1885. They were rather younger than 

 those discovered by Fankhauser, and enabled Bruchmann 'to confirm and slightly extend Fank- 

 hauser's observations. But the most important contribution to our knowledge of the life-history of 

 the group is that of Treub in the Ann. d. Jard. Bot. d. Buitenzorg, iv, 1884, a contribution which 

 modifies considerably the statements in the text. Treub has succeeded in cultivating at Buitenzorg 

 the spores of Lycopodium cernuum and has also found prothallia growing naturally. He describes 

 and figures the mature prothallium as a cylindrical body about -% of an inch long, growing 

 vertically, yellowish below and bright green towards its summit where it is surrounded by a tuft of 

 lobes, its base clothed with rhizoids among which is a tubercle (primary tubercle) representing the 

 pluricellular product of the apical cell formed by division of the germ-tube (the first stages in 

 germination are like those described by De Bary in L. inundatuni). Round the summit of the 



