THE GENERAL CONSTITUTION OF LIVING BEINGS. 69 
fluids, of the peculiarities they present according to ages, 
species, and morbid conditions, they belong to general anat- 
omy. Robin has pointed out how they become grouped 
and transformed in the cycle of life.’ 
The immediate principles, gathered in a fixed order, 
and with a peculiar structure, form corpuscles of different 
kinds, but always extremely fine and delicate, only visible 
with the aid of highly-magnifying microscopes, and which 
are called anatomical elements. These elements, placed 
in contact and intertangled in a thousand ways, form the 
tissues of the organs, and it is essentially in them that all 
the forces of the living being dwell. More complex than 
some of the infusoria (monads, amoebe), they stand as tiny 
organisms composing in federation the organism of the 
individual. Thus the physiological simplifications of mod- 
ern science have no other object than, by processes of sa- 
gacious analysis, to seize upon these active monads that are 
counted by myriads. ‘These are the simple bodies of biology, 
not less indispensable for the clear rendering of vital facts 
than those which the genius of Lavoisier has the honor of 
discovering were to the understanding of chemical facts. 
Among the anatomical elements a distinction is made be- 
tween cells, fibres, and tubes. Cells are spheroidal corpus- 
cles, polyhedral or disk shaped, having very nearly equal 
dimensions in every direction, varying from five thou- 
sandths to one-tenth of the thousandth part of a metre. 
They are formed of a mass as a base, seldom having a cay- 
ity, but often with one or several nuclei distinguishable 
within it, which are sometimes provided with secondary 
nuclei. These elements are the ones most generally dis- 
tributed through the system. The cellular shape belongs 
indeed to the red and white globules of the blood, to the 
elements of the bones and their marrow, to those of the 
central nerve-substance and the ganglions, to those of the 
1 See, on this subject, the introduction to my book on “The Humors.” 
