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wheat and clover, the carbon, hydrogen, and oxygen again 
increase ; in the clover the amount of nitrogen also increases, 
but in the absence of all manure the nitrogen of the wheat 
remains stationary. 
The bearing of these facts upon the subjects of nutrition 
and development was pointed out, and the analogy between 
the physiology of plants and animals in these functions was 
indicated. As in the animal ovum, so in the seed, the 
genesis of life receives its first impulse from the constituents 
of the seed, and most plants continue for some time to draw 
from this source a portion at least of their powers of growth. 
The experiments might perhaps lead to more definite views 
regarding the distinctions between growth, development, 
and nutrition. 
The source from which the power of growth appears to 
spring was pointed out by an appeal to M. Boussingault’s 
experiments. 
The elements which are used up during early growth are 
the carbon and oxygen and to a certain extent the hydrogen 
of the seed. During germination the starchy portions of 
the seed, by a species of fermentation, under the influence of 
warmth and moisture, and also probably by the molecular 
action of the nitrogenous germ, become changed into sugar 
and other soluble substances, and these are slowfy disinte- 
grated and burnt by a kind of respiration, and heat or other 
energy is developed. The most important agents in assist- 
ing the processes of growth are hydrocarbonaceous particles 
in their course of transformation, and there is little doubt 
that the heat-energy of these compounds bears some import- 
ant relation to active life. 
This fact was placed in apposition with the recent inves- 
tigations of Messrs. Fisk and Wislieenus, Frankland and 
Haughton, upon the sources of mechanical power in animals. 
It seems probable that the oxydation of carbonaceous com- 
pounds in animals has something to do, not merely with the 
