SPERMATOPHYTES 309 



into two, four and then eight, giving rise to the embryo sac 

 (page 96), which is the female Gametophyte. The synergids 

 a,nd egg (page 97) correspond to the archegonium of the pre- 

 ceding groups. 



The stamens are the micros porophy 'Us , the chambers of the 

 a,nther are the micros porangia and the pollen grains are the 

 microspores. The division of the microspore results in a very 

 small and simple male Gametophyte and antheridium bearing 

 two sperm cells. Fertilization has been described (page 98). 



The Finales includes but one family, the Coniferm, which 

 contains several genera as follows : 



1. Pinus, leaves in clusters of 25 ; staminate cones at base 

 of new shoot in spring, pistillate cones single or grouped back of 

 terminal bud or lateral on new shoot. Mature fruiting cone 

 consisting of imbricated, woody carpels or sporophylls, persistent, 

 spreading when ripe and dry. Seeds nut-like, with fragile wing 

 and two for each carpel. The most common species are P. strobus 

 (white pine), P. toeda, (loblolly or old field pine), P. rigida 

 (pitch pine), P. pungens (table mountain pine), P. virginiana 

 (Jersey or scrub pine), P. lanksiana (gray or northern, scrub 

 pine), P. echinata (yellow pine), P. resinosa (red pine) and 

 P. palustris (long-leaved or Georgia pine). 



2. Picea, leaves sessile and keeled on both sides; staminate 

 cones axillary and on shoots of the preceding year;, pistillate 

 cones terminal and maturing during first year ; carpels thin and 

 persistent. The most common species are P. mariana, (black 

 spruce) and P. canadensis (white spruce). 



3. Tsuga,, leaves flat and petioled ; staminate cones in axils 

 of last year's leaves ; pistillate cones at end of last season's lat- 

 eral branchlets ; cones maturing during first year and pendulous, 

 carpels thin and persistent. This genus is represented by T. 

 canadensis (hemlock). 



4. Abies, leaves solitary, keeled and persistent; staminate 

 cones in axils of last year's leaves ; pistillate cones erect and on 

 upper side of branches ; cones maturing during first year, car- 



