VASCULAR FLOWERLESS PLANTS. 79 



they spring from all parts of the stem in contact with.the 

 earth, and are not confined to one of its extremities. 



106. The reproductive capsules are situated in the axils of 

 the metamorphosed leaves of the stem, which form long, 

 yellow, clavate spikes in Lycopodium clavatum ; whilst, in 

 other species, as in Lycopodium lucidulum, these leaves 

 retain their usual green color and appearance, being appa- 

 rently unaffected physiologically, by being in the immediate 

 neighborhood of the fruit. 



107. These plants abound in warm, moist, insular climates, 

 and are especially interesting as being allied especially to the 

 fossil plants called Lepidodendrons. The Lepidodendrons are 

 very abundant in most English coal-mines, where some have 

 been found nearly entire from their roots to their upper 

 branches, one specimen being forty feet high and thirteen 

 feet in circumference. These fossil plants are called Lepi- 

 dodendrons, or scaly trees, because their cylindrical stems are 

 covered with marks left by the fallen leaves. In their struc- 

 ture, they accord with the Lycopodiums ; they are, in- fact, 

 gigantic club-mosses. 



108. The Lycopodium squamatum, of Brazil, exhibits a 

 very interesting case of locomotive power. This plant, when 

 deprived of water during the dry season, unroots itself from 

 the ground, rolls itself into a ball, and becoming withered, 

 and apparently devoid of life, is driven hither and thither by 

 the wind, until it reaches a moist situation, when it speedily 

 unrolls itself, sends down its roots into the soil, and spreads 

 out its leaves, which from a dingy brown speedily change to 

 the bright green hue of active vegetation. 



