142 Prof. LeConte on the Correlation of Forces. 
would enter as an element in the calculation. Also, it would 
seem that those plants especially which frequent rich shady 
spots, should exhale proportionally more CO* and less oxygen, 
than those loving thin soils and sunny places. 
In plants, then, there are two sources of organizing force, the 
relative proportion of which varies infinitely, according to the 
amount of light, heat, colour of the plant and richness of the soil 
in organic matters. The two sources are immediately, Ist, the 
decomposition of CO*, 2nd, the decomposition of soluble highly 
carbonized organic matter; remotely, the two sources are light 
and neat. In plants which first take possession of desert spots, 
bare rocks, &c., the first is the only source. In pale plants and 
fungi the second is the only source; but in most plants the two 
are combined in various proportions. The first must of course 
be considered the most fundamental and necessary, the second 
being evidently supplementary. The decomposition of CO* by 
sunlight may be considered as the original source of all vegeta- 
tion; but in most of the higher orders of plants the process of 
nutrition is expedited by the reabsorption of organi¢ matter 
before it again returns to the condition of CO*, HO, and NH?. 
8th. The egg during incubation absorbs oxygen, evolves CO?, 
and probably HO, and loses weight. As the result of this evo- 
lution of CO2, we find the egg developes. What it loses in weight 
it gains in organization. Now what is the source of the organi- 
zing force? It evidently bears a direct relation to the loss of 
weight. Here also, then, we have partial decomposition furnish- 
ing the necessary force. A portion of the organic matter, falling 
from the organic to the mineral plane, sets free a foree which 
raises the remaining portion into a slightly higher condition. 
Heat is evidently the physical force or agent which is trans- 
formed, not direetly but mdirectly, through chemical affinity into 
vital force ; in other words, heat is the agent which effects the 
necessary decomposition. The phenomenon of development of 
the egg is therefore very similar to that of the seed. 
9th. After the hatching of the egg, the animal no longer loses 
weight, because recomposition of food taken ab eaterno proceeds 
pari passu with decomposition. But in this case also decompo- 
sition supplies the force by which recomposition is effected, and 
growth and development carried on. As this is an important 
point, I will attempt to explain it more fully. 
It is well known that in the animal body there are, going on 
constantly, two distinct and apparently opposite processes, viz. 
decomposition and recomposition of the tissues; and that the 
energy of the life is exactly in proportion to the rapidity of these 
processes. Now according to the ordinary view, the animal body 
must be looked upon as the scene of continual strife between 
