Feb. 2, 1882 | 
NATURE 
523 
It is seldom given to one man to fully establish so vast 
an innovation in scientific doctrine’as is the “cell-theory” 
in its complete form. Schwann had not this good fortune. 
His position may be indicated in his own words taken from 
his “ Microscopical Researches” published in Berlin in 1839 
immediately before his departure for the chair at Louvain. 
He says: ‘‘ The elementary parts of all tissues are formed 
of cells in an analagous though very diversified manner, 
so that it may be asserted, zhat there ts one universal 
principle of development for the elementary parts of 
organisms however different, and that this principle is 
the formation of cells. This is the chief result of the 
foregoing observations.” So far Schwann has only been 
confirmed and established by all succeeding observers. 
But when he came to attempt to explain the formation of 
the cells themselves, Schwann signally failed. He pro- 
ceeds: ‘‘A structureless substance is present in the first 
instance, which lies either around or in the interior of cells 
already existing, and cells are formed in it in accordance 
with certain laws.” 
Schwann put forward the notion that cells are pro- 
duced by a sort of aggregative process in a structureless 
mother-substance ; he did not recognize any more than 
his botanical contemporaries the universal origin of cells 
by the division of pre-existing cells, although he very 
fully and correctly identified the animal ovum with a 
single cell, its “germinal vesicle’’ with the cell-nucleus 
and the “germinal spot” with the cell-nucleouls dis- 
covered by him, The enunciation of the doctrine 
“omnis cellula e cellula’”’ was reserved for later workers. 
Von Mohl in plants, and Kolliker and Remak in the 
cephalopods and vertebrates respectively, made obser- 
vations on cell-division which have contributed more 
than any others to the filling out of Schwann’s cell-theory 
by the true doctrine of cell-genesis. It may in truth be 
said that up to the present day a large part of the 
progress in both vegetable and animal histology since 
Schwann’s time, has consisted in the demonstration in 
case after case of the erroneous nature of his doctrine of 
the free formation of cells. 
It is not an easy matter to estimate Schwann’s 
influence in the history of that exact experimental 
physiology, which his researches on muscular contraction 
inaugurated. It is sufficient to point to the enormous 
development of that branch of enquiry within his life- 
time, and to insist upon the wide range of capacity 
(however much we may recognise in its activity the 
influence of the great Johannes Miiller) which enabled 
one and the same man to establish the generalisation 
known as the cell-theory, and, at the same time, to make 
the first exact measurements of the operation of forces in 
a living body, by the methods and instruments proper to 
the physicist. 
blind laws, coeval with the existence of matter itself, cannot be rejected as 
impossible. Reasun certainly requires some ground for such adaptation, but 
for her it is sufficient to assume that matter, with the powers interent in it, 
Owes its existence to a rational Being. Once established and preserved in 
their integrity, these powers may, in accordance with their immutable laws 
of blind Necessity, very well produce combinations, which man.fest, even in 
a high degree, individual adaptation to a purpose. If, however, rational 
power interposes after creation merely to sustain, and notjas an immediately 
active agent then it may, sofar as natural science is concerned, be entirely 
excluded from consiaeration in relation to the creation.” 
(8) The first development of the many forms of organised bodies—the pro- 
gressive furmation of organic nature indicated by geology—is also much 
more difficult to understand according to the teleological than the physical 
view. 
(c) ‘An explanation of the teleological kind is only admissible where the 
physical can be shown to be impossible. Assuredly it conduces more directly 
to the object of science to at least make the effurt to obtain a physical ex- 
planation. And I would repeat that when speaking of a physical explana- 
tion of organic phenomena, it is not necessary to understand an explanation 
tion by £xown physical powers, such, for instance, as that universal refuge, 
electricity, and the like; but an explanation by means of forces which 
Operate /zke the physical forces, in accordance with the strict laws of blind 
necessity, whether they are also to be found in organic nature or not. 
“We set out, therefore, with the supposition that ax organised body is not 
produced by a fundamental power which is guided in its operation bya 
definite idea, but is developed, according to blind laws of necessity, by 
powers which, like those of inorganic nature, are established by the very 
existence of matter.”” 
Schwann’s merit in relation to the doctrine of 
organisms as the cause of putrefaction and of fermen- 
tation, requires to be more fully noticed since the history 
of recent research in these subjects has been such as to 
place a French chemist, M. Pasteur, before the scientific 
world in the position which truly belongs to Schwann. 
The latter appears never to have followed up the brilliant 
experiments by which he demonstrated that putrefactive 
and fermentative processes depend upon the access of 
organic germs to the fluids in which those processes occur. 
But in his “ Microscopic Researches” there is an impor- 
tant note on ‘the theory of fermentation set forth by 
Cagniard-Latour and myself,’’ in which the yeast-cell 
is described as an elementary organism, and its activities 
are discussed as “the simplest representation of the 
process which is repeated in each cell of the living body.” 
It is a remarkable fact that although Schwann communi- 
cated his “cell-theory”” to the Academy of Sciences of 
Paris in 1838, and although his experiments on putre- 
faction and fermentation form the basis of the observations 
which have since been conducted with so much approval 
by M. Pasteur, who has received ample recognition from 
that body, yet no honour of any kind was ever conferred 
upon Schwann by the French Academy of Sciences. 
Even in his old age, at the celebration in 1878, France 
stood last of all European countries —behind even 
Switzerland, Holland, and Spain—in the expression of 
appreciation of, and interest in Schwann’s work, as shown 
by the printed collection of addresses and letters. 
It seems therefore not unfitting to state precisely on 
the present occasion that the discovery of the relation of 
those ubiquitous organisms, the Bacteriaceze, to putre- 
faction (and thus indirectly the immense benefits obtained 
by our Lister’s treatment of wounds) is due in the first 
place to Theodor Schwann, who also discovered the 
organic origin of alcoholic fermentation, and devised and 
carried to a high pitch of perfection those methods of 
experimenting upon this subject which have since been 
amplified and extended by M. Pasteur. 
E, Ray LANKESTER 
WOORARA 
OTWITHSTANDING the deference with which 
every statement that Claud Bernard has made 
ought to be treated, it seems probable that he was mis- 
taken in his ideas regarding the effect of woorara on 
sensory nerves. ‘The indications of sensibility under the 
action of woorara are afforded by the limb of a frog to 
which the poison has not had access, so that the endings 
of the motor nerves in it are not paralysed. On pinching 
a portion of the skin anywhere in such an animal, even 
on the poisoned leg, it is noticed that movement takes 
place only on the unpoisoned one, while all the poisoned 
parts remain perfectly limp and motionless. But this 
movement, while it might indicate pain, does not neces- 
sarily do so, and may only indicate simple reflex action. 
The difference between these two conditions, in which 
the movement is alike, is that which exists between the 
effect of tickling the sole of the foot in man with a 
feather and running a pin into it. In both cases the foot 
would be drawn up, perhaps even more so with the feather 
than with the pin, but the pin would cause pain, and the 
feather would not. The movement of the frog’s leg in 
woorara poisoning much resembles that caused by the 
feather, for it will occur as readily, or ,more so, if the 
brain has been removed. We know that in cases where 
the spinal cord has been broken by accident in man 
reflex occurs in the legs quite readily, but of this the 
patient himself is utterly unconscious excepting by 
seeing the movements in the same way as a by- 
stander. Increased movement, therefore, in the cura- 
rised frog, instead of indicating increased sensibility 
to pain, may only indicate increased irritability of the 
