566 
IN ATMO TE: 
[OcronER 12, 1899 
constant current. But, as Faraday was the first to show, 
small particles of any kind are driven to one or other pole 
when suspended in fluid through which a current is passed, 
and a rod of jelly suffers compression at one end and 
expansion at the other under the mechanical stresses 
produced by the passage of a current. 
The general tone of the book is inspired by an im- 
patience with the laggard pace of knowledge—the 
“foster-child of silence and slow time,” if one may wrest 
a phrase of Keats from its setting—which prompts the 
taunt that the physiology of to-day is impotent in face of 
the simplest vital processes. Unfortunately, it is not 
controlled by a true feeling for the relation of the know- 
ledge of living matter to the progress of the general 
knowledge of matter. The tools with which the attempt 
to fashion a dynamical explanation of the phenomena of 
life must be made are themselves still in the making. It 
is barely ten years since what was practically the new 
science of molecular physics was founded at the meeting- 
place of chemistry and physics by the labours of Guld- 
berg and Waage, Arrhenius, van ’t Hoff, Gibbs, Ostwald 
and others. On the growth of this science the biologist 
must wait, and, though the advances which it has made 
are prodigious, they are concerned wholly with the 
crystalloid type of matter—they have not yet embraced 
‘the colloid type which is the physical basis of life. 
The completeness of our ignorance of the latter type 
is manifested with almost dramatic force when one finds 
all that is known of colloidal matter lying in the compass 
of a page or two of a text-book such as that of Ostwald 
or of Nernst, whereas the account of the crystalloid type 
stretches to many hundreds! Reproaches and hasty 
generalisations are equally out of place in the face of 
‘this colossal ignorance of the elements of the problem ; 
and one feels the practical wisdom of physiological 
workers in devoting themselves to what may be called 
the anatomy of function—that is, the interpretation of 
organ and tissue activities in terms of the fundamental 
properties of living matter, rather than in kicking against 
the barriers which the general state of knowledge opposes 
to the translation of these fundamental properties into 
terms of matter and motion. 
The same lack of a sense of the historical position of 
biology caused Bunge to drift into vitalism, which at any 
rate has the merit of recognising the difficulties which 
stand in the way of a dynamical explanation of meta- 
bolism, irritability, and the recurrent cyclic character of 
the phenomena of life. 
Prof. Verworn, however, is impelled to the opposite 
extreme—a materialism, often rash, which leads him to 
a disastrous quest for “simple explanations,” in which 
his knowledge too frequently becomes wire-drawn to the 
breaking point. The “mechanical explanation” which 
he offers of the “so-called” selection of food will serve 
as an instance. A cell bathed bya nutrient fluid such 
as, e.g., an epithelial cell absorbing material from the 
lumen of the intestine, is likened to a crystal growing in 
its mother liquor. Like its analogue, it withdraws only 
special substances from the common nutrient fluid, “as 
is evident from the fact that gland, muscle and cartilage 
cells produce wholly different and characteristic sub- 
stances.” Hence the conclusion that the selection of 
food is only a special manifestation of chemical affinity, 
NO. 1563, VOL. 60] 
and that “it is an absolutely necessary consequence of 
the fact that the living substance of every cell possesses 
its own specific composition and its own characteristic 
metabolism.” So in place of the healthy recognition of 
a difficulty we are offered a cumbrous platitude and a 
leap in the dark ! 
The simple explanation which is offered of the fact 
“which must otherwise appear very wonderful” (sic), 
that among the innumerable swarm of spermatozoa cast 
into the sea, every spectes finds its proper ovum, also 
deserves mention. It “is explained very simply by the 
further fact that every species of spermatozoon is chemio- 
tactic to the specific substances that characterise the 
ovum of the corresponding species.” The robe of 
modesty is more fitting than the gown of counsel for 
explanations like these ! 
In other cases the haste for simple explanations leads 
to a mode of treatment of problems of acknowledged 
difficulty which intensifies the obscurity. Thus some 
space is devoted to urging that there is no distinction 
between the motor impulse er the electric current in 
their action upon, for instance, muscle fibres and that re- 
lation between motor nerve cell and muscle fibres which, 
when it is broken by severance of the connecting nerve, 
causes degeneration of the latter. This view is dis- 
tinctly opposed to the results of recent work upon 
muscular tone, and upon the effects of section of the 
roots of spinal nerves which tend to emphasise the dis- 
tinction between the calling out of special activity by 
special nervous impulses and the fact that many highly 
specialised cells are dependent for their continued well- 
being, even for their capacity to respond to stimuli, upon 
their functional continuity with other and totally dis- 
similar cells. We are ignorant of the nature of the 
latter relation, though it may well be one of simple 
dynamical equilibrium rather than one dependent upon 
the passage of nervous impulses. But Prof. Verworn 
starts in a panic from this unsolved problem. He sees 
in it a piece of the old mysticism of the vitalists, and, in 
order to compass a simple explanation, trophic relations 
are grouped with the action of electric and chemical 
stimuli and of food into one class which lacks both 
order and form. 
In spite of these defects in general tone, the pages 
of the book furnish abundant justification for the success 
which it has already attained. The point of view which 
the author has adopted has led him to bring together a 
body of facts, many of them little known, in a manner 
which cannot fail to be stimulating and suggestive to 
both physiologists and morphologists. Many gems of 
thought, too, are to be found, especially in the later 
chapters. The sections on the directive effects of 
unilateral stimulation, chemiotaxis, barotaxis, &c., are 
singularly interesting, and so too is the conclusion 
which is drawn from the facts, namely, a_ general 
application of the principle of the specific energy of 
sense-substances. 
“All living substance possesses specific energy in 
Miiller’s sense : with certain limits wholly different stimuli 
call forth in the same form of living substance the same 
phenomena, while, conversely, the same stimulus in dif- 
ferent forms produces an effect wholly different and 
characteristic for every form.” 
