ORIGIN OF THE ANIMATED TRIBES. 8d 



is of such recent origin, that its results cannot be expect- 

 ed to be very clear. Some facts however, are worthy of 

 attention with regard to the present inquiry. It is ascer- 

 tained that the basis of all vegetable and animal substances 

 consists of nucleated cells ; that is, cells having granules 

 within them. Nutriment is converted into these before 

 being assimilated by the system. The tissues are formed 

 from them. The ovum destined to become a new crea- 

 ture, is originally only a cell with a contained granule 

 We see it acting this reproductive part in the simplest 

 manner in the cryptogamic plants. " The parent cell 

 arrived at maturity by the exercise of its organic func- 

 tions, bursts, and liberates its contained granules. These, 

 at once thrown upon their own resources, and entirely 

 dependent for their nutrition on the surrounding elements, 

 develope themselves into new cells, which repeat the life 

 of their original. Amongst the higher tribes of the cryp- 

 togamia, 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."* Here the little cell becomes 

 directly a plant, the full- formed living body. 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 sustentation only to the fluid into which it has 

 been cast, becomes, without further process, the new 

 creature. Farther, 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 ani- 

 malcules. One of the most remarkable of these, the vol- 

 vox globator, has exactly the form of the germ which af- 

 ter 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, producing a revolving motion, or its appear- 

 ance, is partly the cause of the name giyen to this animal- 

 cule. These resemblances are the more entitled to notice, 

 that they were made by various observers, distant from 



* Carpenter's Report on the Results obtained by the Microscope 

 in the Study of Anatomy and Physiology, 1843. 



8 



