ORIGIN OF THE ANIMATED TRIBES. 103 



which the Almighty Deviser might establish all the vegetable 

 forms with which the earth is overspread. ( 47 ) 



We turn to the minutiae of organic structure and embry- 

 ology, as affording us some further illustrations of an instruc- 

 tive kind. It is now ascertained by microscopic research, that 

 the basis of all vegetable and animal substances consists of 

 nucleated cells ; that is, cells having granules within them. 

 Xutriment is converted into these before being assimilated 

 by the system. The tissues are formed from them. The 

 ovum destined to become a new creature, is originally only a 

 cell with a contained granule. We see it acting this repro- 

 ductive part in the simplest manner in the cryptogamic plants. 

 " The parent cell, arrived at maturity by the exercise of its 

 organic functions, bursts, and liberates its contained granules. 

 These, at once thrown upon their own resources, and entirely 

 dependent for their nutrition on the surrounding elements, 

 develop themselves into new cells, which repeat the life of 

 their original. Amongst the higher tribes of the crypto- 

 gamia, the reproductive cell does not burst, but the first cells 

 of the new structure are developed within it, and these 

 gradually extend, by a similar process of multiplication, into 

 that primary leaf-like expansion which is the first formed 

 structure in all plants." (* 8 ) Here the little cell becomes 

 directly a plant, the full formed living being. It is also worthy 

 of remark that, in the sponges, (an animal form,) a gemmule 

 detached from the body of the parent, and trusting for sus- 

 tentation only to the fluid into which it has been cast, becomes, 

 without further process, the new creature. Further, it has 

 been recently discovered by means of the microscope, that 

 there is, as far as can be judged, a perfect resemblance between 

 the ovum of the mammal tribes, during that early stage when 

 it is passing through the oviduct, and the young of the infusory 

 animalcules. One of the most remarkable of these, the volvox 

 globator, can hardly be distinguished from the germ which } 

 after passing through a long foetal progress, becomes a com- 

 plete mammifer, an animal of the highest class. It has even 

 been found that both are alike provided with those cilia, which) 



