Sporangium-bearing Organs of the Lycopodiaceae. 43 
III.— Genus II. Lycopodium. 
I propose to follow Engler and Prantl’s 1 classification of the 
genus Lycopodium, for, although this was chiefly based on external 
characters, it is interesting to find it generally firmly supported by 
the more minute study of the sporangium-bearing organs. Baker’s 
arrangement 3 , is found to be far less useful for the present purpose. 
A. Urostachya, [Selago and Phlegmaria (Baker)J. 
(i) a. Euselago. It is characteristic of this group that any or 
all of the leaves may be fertile ; the sporophylls are closely similar 
to the vegetative leaves and are not aggregated to form a definite 
cone. Fig. 1a, PI. II. is drawn from the apical region of a plant of 
L. selago, showing the simple, crowded sporophylls, bearing 
sporangia which have no special protective apparatus but are 
exposed between the sporophylls. The drawings of separate 
sporophylls of L. selago, (PI. II., Fig. 1. b, c) and L. serration, 
(PI. II., Fig. 1), show still more clearly the unprotected condition of 
the sporangium. 
The position of the young sporangial rudiment was studied at 
the apex of a young plant of L. selago, (PI. II., Fig. 1). It is seen 
that the young sporangium can here hardly be looked upon as foliar 
in origin, for it appears to arise from the meristematic tissue of the 
cone-axis in the axil of the sporophyll. Owing to the growth, later, 
of all the tissues except those between the sporangium and the leaf 
immediately below it, these two organs appear in the adult far more 
obviously associated than they were when young. 3 
The sporangia of the species belonging to this group are all 
large and are borne on stalks of varying length ; these being 
shortest in L. selago, moderately long in tetragonum, fontinalis, and 
lucidulum, and much more elongated in quadrangulum, dichotomutn 
and serration. In every case the sporangium dehisces by means of 
an apical longitudinal slit. A mucilage cavity in the base of the 
sporophyll is present in several of the species {selago, serration, 
lucidulum, tetragonum). In the sporangial stalks of L. serration 
(PI. III., Fig. 2), and L. lucidulum, the walls of some of the cells are 
found to be more or less lignified, 4 thickened at the corners, and 
1 Engler and Prantl; Pflanzenfamilien. Teil I., Abt. 3 (Pritzel). 
2 Baker. Fern-allies p. 7. ; cf. Hooker and Greville, Botanical 
Miscellany, Vol. II., p. 360, and Spring, Mem. del’acad. royale 
de Belgique, XV. and XXIV. 
3 cf. Selaginella ; Bower, 1008, p. 316, Fig. 162. 
4 cf. Cells of sporangial stalk in Bothrodendrou muudum (D. M. S. 
Watson, Brit. Assoc. Leicester Meeting, 1907 ; similar cells 
are also indicated in Miss Bcrridge’s preparations on the 
sporangium pedicel of Speucerites). 
