A Criticism of the Cell-Theory; being an Answer to Mr. Sedgwick's ...

A CRITICISM OF THE CELL-THEORY. 173
from experience, for not long since I was much puzzled by
such a reticulum, and had I been less cautious I should have
published, as a great morphological discovery, statements which
rested on a wholly insufficient basis of experience. The subject
requires further investigation, and the most that one can say
now is, that it is possible that Mr. Sedgwick, good observer as
he is, may have been mistaken. And he will pardon my
observing that the things which he states are not " facts."
They are his own inferences from his own individual observations,
and will require very abundant confirmation before they
can take rank as what we agree to regard as " facts." All the
" facts " we have at present, i. e. the accumulated observations
of hundreds of highly-trained and able observers, are fundamentally
opposed to any such account of protoplasmic growth
apart from nuclear formation as Mr. Sedgwick gives us. But
there is another way of looking at it, namely, that he has only
overstated his case, and that the growth of the tissues in
question resembles the apparent creeping motion of the plasmodia
of the Myxomycetes. That this may be the case is
supported by a study of Mr. Assheton's recent account of the
growth of the mesoblast and of the inner layer of the epiblast
in the embryo of the rabbit. It presents no theoretical difficulties,
but it should be remarked that Mr. Assheton figures
numerous nuclei at the very edge of the growing part of his
reticula, which is consonant with what we know of protoplasmic
growth in other cases, but not with Mr. Sedgwick's
account.
But if Mr. Sedgwick can prove that the reticulum is there
and that it grows and spreads far from the nuclei which subsequently
migrate into it, he must not suppose, as he is
apparently so ready to assume, that the inveterate prejudice
of morphologists will prevent their accepting his conclusions
because of their theoretical difficulties. If his case is proved,
it will be accepted, but he must prove it up to the hilt.
And if he does prove it, what then ? It will be an isolated
case, of secondary significance: merely another addition to
our experience of the very various phenomena displayed in