242 
PHARMACEUTICAL BOTANY 
sperms no recognizable prothallus has been proven to exist; the 
stored food tissue within their seeds is prothallial tissue loaded with 
starch, etc., while that in Angiosperm seeds (endosperm) is developed 
Irom the endosperm nucleus; the mode of growth of their stems is 
always indefinite while that of Angiosperms is either indefinite or 
definite. 
The groups still extant are the Cycads or Fern Palms, the Gne- 
tums, the Ephedras, the Ginkgos and the Conifers. Of these the 
Conifers comprising over 300 species are the most numerous. Manv 
of them yield valuable products to pharmacy and the arts. 
Fig. 1 16. — Cyas revoluta, showing terminal bud of foliage-leaves just opening. 
(Gager.) 
The Conifers include the pines, spruces, hemlocks, cedars, firs, 
arbor vitse, chamaecyparis, and larches. All of their number are 
evergreen except the larches, which drop their foliage upon the 
advent of winter. 
I. Order Coniferales. — Trees with a single upright stem which 
develops side branches that spread out horizontally and taper to a 
point at the summit, giving the crown of the tree the appearance of 
a huge cone, rarely shrubs. 
