A CRITICISM OF THE CELL-THEORY. 169 
As a physiological concept it is hardly less useful, though 
reflection may induce us to abandon the ‘ cell-republic” 
theory, as, indeed, it has been tacitly abandoned by many. 
I take it that the scheme of von Sachs very nearly expresses, 
in general terms, the physiological importance of the cell. 
An organism is a protoplasmic body, coherent in itself, which 
grows, and as it grows it is divided by cleavage into innu- 
merable corpuscles, and it appears that the more vigorously 
this formatien of corpuscles proceeds with the nutrition of the 
organism, the higher also is the development attained by the 
total organisation. Nor does this statement stand in any con- 
tradiction to the original theory of Schwann, from whom I 
may quote two more passages: ‘‘ The elementary parts of all 
tissues are formed of cells, in an analogous though very 
diversified manner, so that it may be asserted that there is 
one universal principle of development for the elementary 
parts of organisms, however different, and that this principle 
is the formation of cells.’ And again, he says of the relations 
of cells to one another, ‘‘ Each cell is within certain limits an 
individual, an independent whole. The vital phenomena of 
one are repeated, entirely or in part, in all the rest. These 
individuals, however, are not ranged side by side as a mere 
aggregate, but so operate together in a manner unknown to 
us, as to produce a harmonious whole.” It should be remem- 
bered that Schwann regarded cells as so many separate vesi- 
cles, and when allowance is made for this error, the second 
part of the last passage must be allowed to have great signifi- 
cance. The subordination of the parts to the harmonious 
whole, leading to the loss of individuality of the parts, in 
animal tissues, was insisted on by Hickel in his ‘ Generelle 
Morphologie.’ The first of the two sentences which I have 
quoted from Schwann is even more true to-day than when it 
was written, for we have got rid of the cell-forming matrix, 
the cytoblastema ; and I would wish to insist on this passage 
as expressing in the clearest possible language the cell-theory 
as we understand it to-day. 
From this standpoint we can see, obscurely it may be, why 
