358 



SYSTEMATIC BOTANY. 



for those of Gymnosperms and Angiosperms respectively have been pro- 

 posed. The embryo-sac, corresponding to the macrospore of higher 

 Cryptogams, becomes filled with cellular tissue forming an endosperm, 

 which is absorbed after a time in the cases where the seed takes two years 

 to ripen, and is re-formed the following spring. The formation of the 

 archegonia or corpuscula will be subsequently alluded to. After fertili- 

 zation the corpusculum develops into a pro-embryo, from the extremity of 

 which the embryo proceeds. Pinaceae and Taxaceae agree with Dicoty- 

 ledons in habit ; but the foliage of the latter approaches that of Ferns, 

 while there are relations between their inflorescence and that of the 

 Lycopodiaceae ; Gnetaceae approximate to Casuarinaceae and Chloran- 

 thaceae in habit ; and perhaps Ephedra may be compared with Equisetum. 

 The pollen corresponds to the microspores of Selaginetta, the division of 

 its cells corresponding to the male prothallus of those plants. 



PINACE^E OR CONIFEBJE. THE PINE OEDEB. 

 Order Coniferae, Bentli. et Hook. 



Diagnosis. Trees or shrubs, of exogenous structure (see post], 

 mostly with evergreen, linear, needle-like or lanceolate leaves, 

 sometimes tufted, sometimes imbricated, monoecious or dioecious ; 

 the female flowers in cones, consisting of imbricated scales or open 

 carpels arising from the axils of bracts, and bearing (figs. 444 A 

 & 445) 2 or more ovules on the upper face ; fruit a woody cone 

 (iig. 309, p. 152) or a succulent berry formed by coherence of a few 

 fleshy scales (galbulus). 



ILLUSTRATIVE GENERA. 



Suborder 1. ABIETINE^. Ovules 

 inverted, with the micropyle next the 

 base of the carpel ; pollen oval. 



Pinus, L. 



Abies, Tournef. 



Araucaria, Juss. 



Subord. 2. CUPRESSINE^E. 

 erect, with micropyle superior 

 len spheroidal. 



Juniperus, L. 



Thuja, Tournef. 



Cryptomeria, Don. 



Cupressus, Tournef. 



Taxodium, L. C. Rich. 



Ovules 

 ; pol- 



Afflnities, &c. The above diagnosis gives the essential character of this 

 Order, which, however, deserves a little detailed notice, on account of the 

 modifications occurring in the different genera, as well as on account of 

 the difficulties which the structure of the inflorescence may present to 

 the student. 



Among the Abietinece, in the common Scotch Fir (Pinus sylvestris) the 

 male inflorescence appears in the form of a compound spike, each branch 

 of which consists of a number of anthers arranged in a catkin ; each anther 

 is represented simply by a scale, arranged like the leaves, having 2 

 parallel pollen-cells, one upon each side of a connective which is produced 

 into a little tongue beyond the pollen-cells (fig. 447), and resembling the 

 scales of Equisetum. By A. Braun the entire male inflorescence was con- 



