310 



LESSONS WITH PLANTS 



bearing naked ovules, comprise the pines, spruces, 

 firs, cedars, yews, junipers, cypresses, ginkgos, 

 and the like. 



Fig. 324. 

 Cone overgrown by the branch. 



376a. Far the larger part of flowering or seed-bearing plants 

 (or the spennatophyta) are angiosperms. The gymnospenns are very 



old types, geologically con- 

 sidered. They comprise 

 such plants as the pines, 

 spruces (and all the Conif- 

 ers or cone-bearing plants), 

 cedars, yews, cypresses and 

 ginkgo, — the last cultivated 

 as an ornamental tree from 

 China and Japan. There 

 are various fundamental 

 differences between the an- 

 giosperms and the gymno- 

 sperms, but they are chiefly 

 such as the pupil can un- 

 derstand only when he 

 takes up the study of com- 

 parative anatomy and morphology ; we cannot, therefore, give this 

 type of plants adequate treatment in this book. 



3766. Botanists are not agreed as to the morphology of the 

 cone of the gymnosperms. Some consider that the ovule-scale 

 represents an open carpel. Others think that this scale represents 

 a placenta, and that the subtending bract is homologous with a car- 

 pel. Others accept neither view. 



Suggestions. — The pupil knows that the lowermost and upper- 

 most leaves and buds on any branch (not counting the terminal 

 bud) are commonly smallest and apparently least efficient (42). Let 

 him examine pine cones, to se^ in what part of the cone the most 

 and best seeds are borne. He\should also determine the position 

 of the cones of the different pines and spruces: upon what part 

 of the tree they are borne, how many together, and how long 

 they persist. 



