FAMILIES OF FLOWERING PLANTS. 3 



cropjxires, which are the active agents in fertilization. The feiunie 

 spor{)|)hylI l)ears macrosporanijes containing niacrospores. The hitter, 

 when fertilized, develop embryos, which become ullimalely new 

 individuals. Amonir the tiowerin<j plants these various oraans have 

 received special designations somewhat more familiar in general usage. 

 The male sporophyll is known as a stamen, the microsporange as an 

 anther-sac, one or more of which constitute an anther. The female 



Fig. 1. — Base of a Californian Sequoia or "big tree," which represents a vanishintr 

 type of gymnospermous vegetation. (After Pinchot. Primer of Forestry. Bull. -U. 

 Div. of Forestry, U. S. Dept. of Agric). 



sporophyll consists in the majority of flowering plants of a s{)eci.'illy 

 modified leaf called a carpel, which serves as a pouch to contain the 

 macrosporanges or ovules. The carpels collectively form a structure 

 known as an ovary, which is said to be monocarpellary or polycar- 

 pellary according to the number of divisions it contains. Each ovule 

 includes a single macrospore or embryo-sac, and the fertilized ovule 

 becomes a seed, the ripened ovary and its contents a fruit. A flower, 

 on the other hand, or rather the conspicuous portion thereof (calj^x and 

 corolla) is merely a group of modified leaves serving as a protection to 

 the enclosed stamens and ovary, which are vital organs. The showy 



