564 



NA TURE 



[October 14, 1897 



essentially a work of reference, and is rendered the more 

 valuable in this respect by the addition of a fair biblio- 

 graphy appended to each chapter. The physiological 

 character of the work will be at once recognised when 

 the subjects treated of are enumerated. The action of 

 chemical agents upon protoplasm is first dealt with, 

 including the action of drugs and the relation between 

 molecular composition and physiological action. The 

 question of acclimatisation (immunisation) is considered 

 both for inorganic and organic poisons. The author 

 does not confine himself to the action of external 

 agents upon single cells or unicellular organisms, but 

 includes their action upon the whole organisation of 

 individuals belonging to the higher vertebrates. Thus 

 we find such experiments as those of Calmette upon 

 immunisation to snake venom, and those of Nuttall 

 and Thierfelder upon bacterium-free guinea-pigs, laid 

 under contribution. The influence of oxygen upon 

 the movements of bacteria and unicellular organisms, 

 and the phenomena of chemotaxis in general occupy a 

 special section of the chapter on chemical agents. The 

 interesting observation of Roux, that isolated cells from 

 the blastula of the frog move slowly in fluid, their move- 

 ments being influenced by the presence of neighbouring 

 cells, is referred to as a special morphologically in- 

 teresting case of chemotaxis. The effect of adding or 

 removing water to or from protoplasmic organisms : 

 their vitality in circumstances producing desiccation, 

 and the limits of such desiccation in the case of lower 

 organisms, germs and seeds. The osmotic effects of 

 solutions (with a very clear and interesting account of 

 de Vries* fundamental experiments) ; this section in- 

 cludes also the acclimatisation of organisms to solu- 

 tions of salt, e.g. of fresh-water organisms to sea- 

 water, and vice versd. The effects of mechanical dis- 

 turbance — mechanical stimulation— upon amoeboid move- 

 ments, and upon direction of locomotion, including 

 the effects of fluid currents (rheotaxis). The effect of 

 gravity (geotaxis). That of electricity, and the differ- 

 ences displayed by different organisms in responding to 

 galvanic currents, some, such as most Protozoa and 

 Mollusca, responding to the positive pole (reacting at 

 the anode on closure of the current) — anode-excitable or 

 anex type — others, such as the Arthropoda and Verte- 

 brata, responding to the negative pole (reacting at the 

 kathode on closure of the current) — kathode-excitable or 

 katex type. The phenomena of electrotaxis (positive 

 and negative) in various organisms, the following general 

 law being laid down for Metazoa : "Positively electro- 

 tactic organisms exhibit the katex type of irritability ; 

 and negatively electrotactic organisms exhibit the 

 anex type, or, in general, the organism turns tail to 

 the exciting pole." The action of light upon proto- 

 plasm, especial attention being given to the experi- 

 ments of Engelmann with the microspectro-photometer, 

 and those of Marshall Ward on the bactericidal action 

 of the luminous rays. The phenomena of phototaxis i 

 and photopathy, including the effects of light 

 in producing both bodily movements of organisms and 

 movements of the protoplasm of cells, e.g. of pigment 

 cells in the skin and retina. . The effect of heat upon 

 protoplasm, including the phenomena of rigor, both 

 NO. 1459, VOL. 56] 



temporary and permanent, in muscle, with an interesting 

 section on acclimatisation of organisms to extreme 

 temperatures. 



These are the subjects treated of, and it will be seen 

 from the mere enumeration of them that the book covers 

 a vast field of research : too vast to be really adequately 

 dealt with within the modest limits of 280 octavo pages ; 

 nevertheless, it offers a valuable aid to the English 

 student of biology. If we compare it with Verworn's 

 well-known "Allgemeine Physiologie" (a better term, in 

 our opinion, than experimental morphology — at least 

 as applied to the subjects treated in this part of the work), 

 which is a larger book covering the same ground, we 

 find far fewer original experiments and observations, 

 but a more complete account of the literature. Never- 

 theless, there are several noteworthy omissions. In 

 dealing with the effects of chemical agents, the ques- 

 tion of antagonism is untouched, and the important 

 work of Ringer and others upon this subject is un- 

 noticed. The same may be said for the work of Brunton, 

 Cash, and others upon the relations between chemical 

 constitution and physiological action. The chemical 

 changes in protoplasm attendant upon its activity, and 

 the effect of external agents upon such changes, are 

 hardly so much as alluded to. The name of Romanes is 

 nowhere mentioned, although his experiments upon the 

 influence of chemical agents, of light, of gravity, and of 

 electricity upon both animal and vegetable organisms 

 are full of interest. But perhaps the most serious 

 omission is the relative lack of allusion to the 

 effects of external agents upon plant protoplasm 

 In view of the light which may be thrown upon the 

 phenomena exhibited by animal organisms by an account 

 of those exhibited by plants under similar circumstances, 

 it is in the highest degree desirable to bring the evidence 

 derived from the two kingdoms together. For although, 

 as the author puts it, protoplasm "must be a very dis- 

 similar thing in different organisms," there must, never- 

 theless, be somewhere a fundamental identity between 

 protoplasm from all sources. And, indeed, the author 

 admits this : 



" It is with living organisms that we have to deal, and,, 

 accordingly, no distinction should be made between 

 animals and plants. I have, indeed, made no such dis- 

 tinction ; nevertheless, tastes and training have led me 

 to lay especial stress upon animals. Even this is un- 

 fortunate, for the problem with which we are concerned 

 is precisely the same problem in all living organisms^ 



We must, however, take the book as we find it, and 

 although one could have wished it to be more developed 

 in certain directions, it is still the most complete account 

 in the English language of what may be termed (with 

 Verworn) general physiology. This is a subjiect the 

 study of which has increased so largely of late years, that 

 there is hardly room for it to be more than merely touched 

 upon in text-books of physiology ; it has, in fact, grown 

 into a self-contained branch of that science, with a 

 more or less morphological bearing, and, as with tlxe 

 case of the morphology of the cell, is beginning to require 

 a text-book to itself. We are glad to welcome Dr. 

 Davenport's book as an attempt to furnish us with such 

 a text-book in our own language. 



