118 OBJECT LESSONS IN BOTANY. 



often, also, without steins. Hence we may say of the Cryj>- 

 togams that they are not only Jlowerless, but seedless, and 

 often leafless and stemless. 



252. We will now dismiss the Cryptogams for the present 

 and consider the Flowering Plants (Phsenogams), as one sub 

 kingdom; how shall this be divided? Every one notices a 

 striking difference between plants with parallel-veined leaves 

 and those with net-veined leaves. The former have their 

 flowers three-parted, while the latter have their flowers two, 

 four, or five-parted, &c., the former have seeds one-lobed 

 (monocotyledoned, Less. 15), the latter, two-lobed (dicotyle- 

 doned, Less. 15). Let us, then, divide the Phsenogamia into 

 two provinces ; as Nature has already done. 



Fig. 3-">9. Cross-section of an exogenous stem (Elm), of two years growth : 1, tlie 

 pith; 2, 8, two layers of wood ; 4, the bark. Fig. 360. Cross-section of an endoge- 

 nous stem (Corn), allowing no distinction of layers. 



253. We may call these two provinces severally, the Exo- 

 GENS and the ENPOGENS: two Greek words denoting outside 

 growers, inside-growers, referring to their modes of growth. 



254. Now, taking such an Exogen as the Apple-tree, and 

 such an Endogen as the Indian Corn, we may distinguish 

 them thus : The Exogen has its wood, if any, arranged in con- 

 centric rings, or layers, as seen in Fig. 360 ; the outer 'ing 



252. Show how the Flowering Plants are divided. 253. Please give <he 

 character of an Exogen ; an Endogen. Mi aning of these two words V 



