LITERARY NOTICES. 



Loeb, Jacques. The Dynamics of Living Matter. Columbia University Biological Series. VIII. 

 The Macmillan Company, New York. 1906. xi + 233. $3.00. 



In the twelve lectures which constitute this volume the author deals rather sum- 

 marily with the chemistry, physical constitution and manifestations of living mat- 

 ter. Living organisms are considered "as chemical machines, consistingessentially 

 of colloidal material, which possess the peculiarities of automatically developing, 



preserving, and reproducing themselves It is the purpose of these lectures 



to state to what extent we are able to control the phenomena of development, self- 

 preservation, and reproduction" (p. i). 



After the introductory lecture, which is devoted to the presentation of the author's 

 general point of view and aims, come five lectures on the chemical and electrical 

 phenomena in living matter. The author's purpose is to indicate the present status 

 of our knowledge of the physical chemistry of protoplasm rather than to discuss 

 facts or problems. Three lectures treat of the influence of heat and light on living 

 matter and of heliotropism and the tropisms in general, and the remaining lectures 

 present certain facts ol development, especially those of fertilization, heredity and 

 regeneration. 



Scarcely any of the material of the book is presented for the first time, and it is 

 therefore unnecessary for us to attempt to restate the facts which the author has 

 assembled. Still less is it necessary to restate his aims, his theoretical positions 

 and his interpretation of the recent progress in bio-chemistry. It will suffice for 

 this review that we note the general make-up and characteristics of the book and 

 the content of those portions of it which deal with the nervous system and animal 

 behavior. 



The property of irritability, for example, is described as follows: "the normal 

 qualities, especially the normal irritability, of animal tissues depend upon the 

 presence in these tissues of Na-, K-, Ca-, and Mg-ions in the right proportion; 

 that these ions are at least partly in combination with colloids (proteids or higher 

 fatty acids or possibly carbohydrates), and that any sudden change in the relative 

 proportions of these ion lipoids or ion proteids or ion carbohydrates alters the proper- 

 ties of the tissues and gives rise to an activity or an inhibition of the activity, accord- 

 ing to the sense in which the change takes place." And further concerning other 

 organic processes: 'T believe that the natural rhythmical processes, such as heart- 

 beat, respiration, etc., are due to a substitution of certain metal ions for others, 

 these substitutions being caused by the enzymatic processes going on continually 

 and by which, among others, metal ions are freed from certain combinations, and 

 rendered available for others, as seems to be the case in the action of rennet in the 

 coagulation of milk" (p. 95). The above quotation will serve to indicate the use 

 which Loeb makes of bio-chemistry. It is of interest to note that he now believes 



