526 Ihe American Naturalist. [June, 
A mean of two analyses of the albumen or stored food of the 
plant seed is :§ 

Carbon . Be ae oy i i R O: 
Hydrogen . ; : : ‘ 7.29 
Oxygen ‘ 7 ; : i 222.85 
Nitrogen . : s i er 15.78 
Sulphur . ; i ‘ eS .40 
99-43 
The same elements enter into the composition of the protoplasm 
of animals, as may be seen from Robin’s analysis of the amniotic 
fluid of a fecundated ovum, etc., etc. (Flint’s Text Book of Phy- 
siology, p. 903). 
In the main these elements of the protoplasm of both plants and 
animals may be regarded as hydro-carbons, or hydrogen and car- 
bon with occasional nitrogen and oxygen, drawn from the soil and 
air into the plant, and from the plant into the animal, and expended 
by both as fuel, producing the motor known as vital force. It 
has been said that in the main constituent of this material were 
_ hydrogen and carbon, but it was not implied that these were the 
only constituents of this substance. 
What we call “ nature” acts in this as in so many other in- 
stances as a prudent speculator who will not entrust all his eggs 
to one basket. An analysis, however crudely conducted, will de- 
tect in the simplest food-stuff of plants, besides hydrogen and 
carbon, sulphur, phosphorus, chlorine, potassium, sodium,and cal- 
cium. More careful analysis of larger amounts of material will detect 
the presence of many other and rarer substances, iron, copper, 
iodine, etc. Still more delicate tests increase th ber of chemical 
elements which are present, either as accessories, as “rare” or 
“very rare ” concomitants. 
It is not an unjustifiable generalization to say that the number 
of chemical elements contained in the “albumen” of a seed-sac 
or the amniotic fluid of a mammal increases with every increased 

8See Dragendorff’s Plant Analysis, p. 288, N. Y., Vail & Co., 1887. 
