1864.] Carrnnter on Correlation of Physical and Vital Forces. 87 
tain the ordinary processes of vegetation, a special provision appears 
to be made in some instances for the evolution of force in the sexual 
apparatus itself, by the retrograde metamorphosis of a portion of the 
organic compounds prepared by the previous nutritive operations. This 
seems the nearest approach presented in the Vegetable organism, to 
what we shall find to be an ordinary mode of activity in the Animal, 
That the performance of the generative act involves an extraordinary 
expenditure of vital force, appears from this remarkable fact, that blos- 
soms which wither and die as soon as the ovules have been fertilized, 
may be kept fresh for a long period if fertilization be prevented. 
The decay which is continually going on during the life of a Plant 
restores to the Inorganic world, in the form of carbonic acid, water, 
and ammonia, a part of the materials drawn from it in the act of vege- 
tation; and a reservation being made of those Vegetable products which 
are consumed as food by Animals, or which are preserved (like timber, 
flax, cotton, &c.) in a state of permanence, the various forms of decom- 
position which take place after death complete that restoration. But 
in returning, however slowly, to the condition of water, carbonic acid, 
ammonia, &e., the constituents of Plants give forth an amount of Heat 
equivalent to that which they would generate by the process of ordi- 
nary combustion ; and thus they restore to the inorganic world not 
only the materials but the forces, at the expense of which the Vegetable 
fabric was constructed. It is for the most part only in the humblest 
Plants, and in a particular phase of their lives, that such a restoration 
takes place in the form of motion ; this motion being, like growth and 
development, an expression of the vital activity of the “ zoospores” 
of Algz, and being obviously intended for their dispersion. 
Hence we seem justified in affirming that the Correlation" between 
Heat and the Organizing force of Plants is not less intimate than that 
which exists between Heat and Motion. The special attribute of the 
Vegetable germ is its power of utilizing after its own particular 
fashion the Heat which it receives, and of applying it as a constructive 
power to the building-up of its fabric after its characteristic type. 
