The Cactus. 219 



could infer their capability of resisting influences so generally 

 destructive to vegetation. But it is with the plant as it is 

 v jth the animal. The more simple and lowly the being, the 

 ater is usually its tenacity of life under circumstances 

 which depress the vital powers of higher kinds, while the in- 

 fluences which they require are often too powerful for it. Thus, 

 Mosses and Lichens, over stimulated by heat and dryness, 

 either in summer; but vegetate freely at a season when there 

 jg no other vegetation, and when their humble fabrics cannot 

 De overshadowed by a ranker growth. Mosses were fanci- 

 fully termed by Linnaeus, servi, servants, or workmen ; for they 

 seem to labor to produce vegetation in newly-found countries, 

 where soil can scarcely yet be said to exist. This is not, 

 however, their only use. They fill up and consolidate bogs, 

 and form rich vegetable mould for the growth of larger plants, 

 which they also protect from cold during the winter. They 

 likewise clothe the sides of lofty hills and mountain ranges, 

 and powerfully attract and condense the watery vapors float- 

 ing in the atmosphere, and thus become the living fountains 

 of many streams. They are sometimes 30 completely dried 

 up by drought, that they escape notice, and then when moist- 

 ened by rain, they appear to have suddenly clothed a barren 

 heath, or overspread a dry wall with verdure. 



THE CACTUS. 



All the species of the Cactus tribe are destitute of true 

 leaves, except when they are first beginning to grow. Just at 

 that time they do indeed produce little succulent bodies, which 

 we know to be rudiments of leaves ; but such parts drop off 

 soon after they are born, and the only representatives they 

 leave behind are the stiff, hooked spines, with which so many 

 species are covered. The parts which are mistaken for leave? 

 in the Indian fig, or some of the more common species of 

 Cereus, are only the flattened joints of the stem. 



It would be difficult to find any race of plants, where a 



