VEGETABLE DISSEMINATION. 509 



plant is formed, while the runner continues its course forming other similar plants 

 as it progresses. 



The best illustrations of this mode of dissemination are the strawberry and 

 the cinquefoil. Rising still higher; we find plants with an upright mode of growth, 

 that bend over till their tips come in contact with the soil where they take root 

 and form new plants. In this manner the species travels, making a ^^^m feet of 

 progress each year. The hobble-bush and black raspberry are good examples 

 of this mode. 



Many trees and plants, when their branches are brought into contact, with 

 moist soil, will take root and produce new plants at a considerable distance from 

 the one to which they are attached. The grape and gooseberry are familiar ex- 

 amples; but nearly all kinds of vegetation will do likewise if the conditions are 

 exactly favorable. Still another method of extending certain vegetable forms is 

 by means of aerial roots that descend from the branches till they come in con- 

 tact with the soil, which they enter and divide as other roots. The circulation is 

 then reversed and the portion above ground becomes a true stem. The stems 

 continuing to elongate, this process is repeated on all sides till a single tree with 

 its multitude of trunks becomes a forest capable of sheltering an army of men. 

 The Banian tree is the most noted illustration of this. A single tree of this 

 species is known to cover a whole island of considerable extent. 



So far we have considered the dispersion of plants only in cases where the 

 young plant remains attached to its parent till it has taken root and become es- 

 tablished and capable of existing as an independent plant, but in none of these 

 cases could the offspring start in life at any great distance from the parent plant, 

 from which it proceeded and of which for a time it formed a part, consequently 

 their progress was but slow ; at most amounting to but a few feet in a year, and 

 in many cases requiring many years to advance but a very few feet. 



But it is evident that it would have required interminable ages to extend any 

 forms of vegetable life, from any center of dispersion, to the different parts of 

 the earth by any of these methods. 



Nature has therefore provided for the general dissemination, reproduction 

 and perpetuation of the various species of vegetable forms through the agency of 

 seeds. Seeds are embryonic plants, in which the germ of the future plant, ac- 

 companied by a sufficiency of plant-food to sustain it till it becomes able to secure 

 its own nutriment from the soil and air, is wrapped in pecuhar cerements and 

 generally enclosed in a leathery, horny or woody covering or shell. These seeds 

 may be carried "to earth's remotest bounds," and preserved for years, and in 

 some cases probably for ages, and then, when placed under favorable conditions, 

 germinate and grow, producing in all essentials an exact counterpart of the plant 

 by which the seed was produced. 



The various means to be employed for the dissemination of seeds so as to 

 scatter as far and wide as possible the plants of different species, seems — I speak 

 it reverently — to have received the most careful attention of the Author of nature. 



VIIT-33 



