100 



The flowers too of 



ENDOGENS. 



Endogens liave in most cases their sepals, petals, and 

 ° stamens corres- 



ponding with the 

 number three, or 

 clearly referrible 

 to that type ; and 

 the pistil usually 

 participates in the 

 same peculiarity. 

 Where such a pro- 

 portion exists in 

 Exogens, it is usu- 

 ally confinedto the 

 sepals and petals 

 by themselves, or 

 to the pistil by 

 itself, not extend- 

 ing to the other 

 organs. In En- 

 dogens it is almost 

 universal in all 

 the whorls of the 

 flower, although sometimes ob- 

 scured b}^ the abortion, dislo- 

 cation, or cohesion of particular 

 parts, as happens in the whole 

 of the extensive natural order 

 of grasses. 



The effect of the manner of 

 growth in Endogens is to give 

 them a very peculiar appear- 

 ance. Their trunks frequently 

 resemble columns rising ma- 

 jestically with a plume of leaves 

 upon their summit; and the 

 leaves, often very large — the 

 {'^ ^^ fan-shaped leaves of some palms 

 ■" " are from 20 to 30 feet wide — 

 have most commoul}^ a length- 

 ened form, resembling a sword 

 blade if stiff, or a strap if weak 

 and broad. These peculiarities 

 are connected with others be- 

 lono-ino' to endoo-enous veo-eta- 



O O O o 



tion in its most rudimentary 

 condition. The embryo of an 

 Endogen is, in its commonest 

 state, a small undivided cylin- 

 der, which protrudes from with- 

 in its substance a radicle from 

 one end and a plumule from a 

 little above the radicle ; in 

 other cases its embryo has a 



Fig. LXXI.— Yucca aloifolia. 



