450 PHANER OGA MS. 



and is attached to the wall of the grain by a very small basal cell ; the apical 

 cell (Fig. 320 B,y) finally enlarges and developes into the pollen-tube. The basal 

 cells of this row appear, after they have lost their contents (in Pinus and Abies), 

 like narrow slits in the thick wall of the pollen-grain, a phenomenon which requires 

 further explanation (see Fig. 320, ^, 17, and 321 IV, e). A peculiarity which dis- 

 tinguishes the pollen-grain of Conifers from that of Angiosperms lies in the rupture 

 and final stripping off of the cuticularised extine by the swelling of its intine (Fig. 

 321, I, II, III). Even in this apparently insignificant fact a resemblance is again 

 seen to the microspores of Cryptogams, and especially to those of Marsileaceae, in 

 which the swelling endospore protrudes from the exospore. 



The structure of the Female Floivers is very different in the different sections of 

 Coniferse, and in some cases the homology of the separate parts is still doubtful. 

 The position of the ovules, as far as can be judged from advanced stages of develop- 

 ment, is, in particular, very variable, and with this is again connected the fact that 

 different opinions may be entertained as to the part which should be called the 

 carpel. The following description of these structures, a full discussion of which 

 is not permitted by our limited space, is drawn immediately from the observation 

 of advanced stages of development; it is possible, however, that the direct obser- 

 vations of the most rudimentary stage will cause an alteration in some points. 



The female flowers of Taxus spring from the axils of foliage-leaves belonging 

 to elongated woody shoots. They have the form of short branches covered with 

 decussate scale-like bracts (Fig. 318, C, D); the axis of the shoot ends in an 

 apparently terminal ovule, the nucleus of which has the appearance of being 

 the vegetative cone of the axis. In Salisburia the female flowers spring from the 

 axils of foliage-leaves belonging to short lateral branches which annually produce 

 new rosettes of leaves (Fig. 317 A)] the single flower consists of a stalk-like 

 elongated axis which bears immediately beneath its apex two or more rarely three 

 lateral ovules. Neither in this genus nor in Taxus are there any foliar structures 

 close to the ovules which either from their position or from any other circumstance 

 can be regarded as carpels. In the genus Podocarpus small flowering shoots are 

 developed, springing in P. chinensis (according to Braun) from the axils of foliage- 

 leaves, in P. chiliiia from the axils of very small scale-leaves at the end of elongated 

 leafy shoots ; they consist of an axial structure slender and stalk-like below, club- 

 shaped above, and bearing three pairs of very small decussate scales. The floral 

 axis terminates between the upper pair; the ovules, in this case anatropous, with 

 their micropyle turned downwards and towards the floral axis, spring from the axils 

 of this pair; one ovule however is usually abortive, and the flower becomes one- 

 seeded. In Phyllocladus the lower lateral branchlets of the leaf-like flattened 

 shoots are transformed into female flowers which are raised upon a pedicel and 

 are swollen above into the form of a club, the large ovules standing (according to 

 a drawing of Decaisne's^), in the axils of small leaves. In these two genera the 

 small scales from the axils of which the ovules spring may be regarded as carpels, if 

 it is thought necessary to assume the existence of these organs. 



* [See Le Maout and Decaisne's Descriptive and Analytical Botany, edited by Dr. Hooker, 

 London 1873, p. 747.] 



