122 CONIFBRALES (RECBNT) [CH. 



fertile and its apex overtops the ovule, while a second bract is 

 sterile. Fig. 684, H shows the strobilus of P. neriifolia in which 

 the lowest bracts are leaf-like and the swollen bases of the upper 

 bracts are fused with the axis and each other to form a receptacle 

 analogous to the flower-axis of Anacardium. P. spicata has a 

 long loose strobilus bearing several ovules (fig. 684, F) ; and in 

 P. Nagi a single seed occurs on an axillary branch bearing small 

 decussate scales: the flesh of the seed is formed from the epi- 

 matium, and the sclerotesta from the integument. 



The seeds of Conifers vary greatly in size and shape : those of 

 some species of Pinus and several other Abietineae have a large 

 wing while others are wingless. The absence of a wing in a fossil 

 seed does not necessarily denote an original feature. The seeds 

 of Cedrus, Abies, Picea, Pseivdotsuga, Keteleeria and Tsu^a are 

 winged. Gliick^ calls attention to difEerences in the relation of 

 seed to wing in certain Abietineae : in Picea the base of the wing 

 covers the seed like a spoon ; in Abies, Larix, and Cedrus the seed 

 lies in a pocket formed by the enclosing wing, while in Pinus the 

 wing embraces the seed like a pair of pincers. In Agathis (fig. 

 682, A) there are two very unequal wings. The much smaller seeds 

 of many Conifers have 2 — 3 wings : in Cupressus they are more 

 or less equal (fig. 684, Q), in Libocedrus and Fohienia markedly 

 unequal ; in Fitzroya and Cunninghamia there are 2 — 3 wings. 

 Our knowledge of the relative vitality of Conifer seeds is meagre^, 

 and from the point of view of the possibilities of dispersal further 

 research is desirable. The viviparous habit of Rhizophora and 

 other Mangrove Dicotyledons, believed by Guppy* to be a primitive 

 feature, is recorded in Podocarpus Makoyi^. 



The relation between nucellus and integument is less uniform 

 in Conifers than in Cycads. In some genera, e.g. Agathis (fig. 

 682, B), Dacrydiutn, Phyllocladus, Fitzroya, Callitris and a few 

 others the nucellus is free from the integument to the base; in 

 Podocarpus the relation is variable ; in Pinus and other Abietineae, 

 in Torreya (fig. 684, V) and some other genera the nucellar apex 

 alone is free. The free summit often has the form of a steep cone : 

 in Araucaria^ and to a greater degree in Saxegothaea (fig. 685, st) 



1 Gliick (02) p. 402. ^ Co^er (09). 3 Guppy (06). 



* Lloyd (02). 5 Seward and Ford (06) B. 



