364 PROGRESS OF GROWTH. 



anything like organization will be developed. All the 

 conditions required for the production of vegetable life 

 appear to show, that it is quite impossible for any kind 

 of plant, even the very lowest in the scale, to be formed 

 in any other way than from an embryo in which are 

 contained the elements necessary for it, and the arrange- 

 ments required for the various processes which are con- 

 nected with its vitality. 



The earth is now covered with vegetable life, but 

 there must have existed a time when " darkness was 

 upon the face of the deep," and organization had not 

 yet commenced tracing its lovely net-work of cells upon 

 the bare surface of the ocean-buried rock. At length 

 the mystery of organic creation began: into this 

 science dares not penetrate, but it is privileged to begin 

 its search a little beyond this point, and we are 

 enabled to trace the progress of organic development 

 through a chain of interesting results which are con- 

 stantly recurring. 



If we take some water, rising from a subterranean 

 spring, and expose it to sunshine, we shall see, after a 

 few days, a curious formation of bubbles, and the 

 gradual accumulation of green matter. At first we 

 cannot detect any marks of organization it appears a 

 slimy cloud of an irregular and undetermined form. 

 It slowly aggregates, and forms a sort of mat over the 

 surface, which at the same time assumes a darker green 

 colour. Careful examination will now show the original 

 corpuscles involved in a net-work formed by slender 

 threads, which arc tubes of circulation, and may be 

 traced from small points which we must regard as the 

 compound atom, the vegetable unit. We must not 

 forget, here, that we have to deal with four chemical 

 elements, oxygen, hydrogen, carbon, and nitrogen, 

 which compose the world of organized forms, and that 

 the water affords us the two first as its constituents, 

 gives us carbon in the form of carbonic acid dissolved 



