October 7, 1910] 



SCIENCE 



469 



tains, vast though this be, but rather in its 

 wholly enlightening effect upon the search for 

 biologic truths, and for this alone it is worthy 

 of deep study and a lasting place in literature. 

 Louis Agassiz Fuertes 



Einfuhrung in die Physiologie der Einzelli- 



gen (Protozoen). By S. von Prowazek. 



Leipzig and Berlin, B. G. Teubner, 1910. 



Pp. 172. 



Ever since the appearance of Verworn's 

 excellent paper on the psycho-physiology of 

 the protozoa in 1889, it has been the hope of 

 many that in these supposedly simple orga- 

 nisms a key would be found to the solution 

 of various perplexing problems in the higher 

 forms; that physiological and psychological 

 processes as well as structures would be dis- 

 covered here in their very inception. Unfor- 

 tunately this hope has not been realized. The 

 life processes in the unicellular forms have 

 been found to be exceedingly complex. Even 

 the anatomy is far .more complex than was 

 formerly supposed. As a matter of fact the 

 more thorough the investigation, the more 

 intricate and involved the physiology and 

 structure of these apparently simple creatures 

 is found to be. Our author, realizing this, 

 says that a protozoan " is in a certain sense a 

 unicellular metazoan," and the establishment 

 of this idea, he asserts, is the underlying 

 motive of the volume under consideration. 



This volume, as the title indicates, is in- 

 tended to serve as an introduction to the 

 physiology of the unicellular forms. The 

 author says it is not a hand-book. In reality, 

 however, it takes the form of a hand-book and 

 might truthfully be called a very brief review 

 or statement of results of original work bear- 

 ing on all functional processes in unicellular 

 forms. The principal topics discussed follow 

 in the order of presentation: The structure 

 of the cytoplasm and the nucleus, both phys- 

 ical and chemical; The nature and function of 

 the surface membrane or layer and various 

 organic bodies within the cell; Respiration; 

 Process of feeding ; Excretion ; Motion and 

 locomotion; Fertilization; Regeneration; Pro- 

 tection; Immunity; Responses to chemicals, 



electricity, light, etc.; Inheritance; Varia- 

 tion, and Mutation. 



While the results of investigation bearing 

 on some of these topics are fairly conclusive 

 and present some coherence, those bearing on 

 others are quite the opposite and the author's 

 treatment of these necessarily consists mainly 

 of a series of dry incoherent statements of 

 experimental results of interest only to those 

 who are in search of a brief account of the 

 work done and the references to such work. 



In general the author's selection and review 

 of papers and his discussion appear sane and 

 trustworthy. He usually presents the liter- 

 ature bearing on both sides of mooted ques- 

 tions without taking a definite stand himself. 

 However, as might be expected in a subject as 

 new as the physiology of the unicellular forms, 

 he supports some conceptions which in the 

 minds of many are erroneous. Among such 

 may be mentioned (1) the idea that the move- 

 ment of certain amoebae can be accounted for 

 by the effect of the environment on surface 

 tension; (2) the idea that the activity and 

 form of organisms is regulated by a non- 

 energetic principle, an entelechy or a psychoid 

 as described by Driesch; (3) the idea that 

 unicellular forms orient and move directly 

 toward or from a region containing certain 

 chemicals or having a given temperature; (4) 

 the idea that there is no selection of food in 

 the protozoa; (5) the representation of the 

 eye-spot of Euglena as a hoUow cylinder. 



The volume in question will no doubt be 

 found valuable principally as a book of refer- 

 ence. Unfortunately, however, it is not well 

 adapted for this use, owing to the very brief 

 table of contents and the absence of an index, 

 and to the fact that the titles of the papers 

 cited are scattered through the body of the 

 text making it difBeult to locate the refer- 

 ences referred to. Moreover, the frequent in- 

 terruption in the text by titles which in many 

 instances appear again and again annoys the 

 reader. S. O. Mast. 



SCIEXTIFIG J0USNAL8 AXD ARTICLES 

 The Journal of Biological Chemistry, Vol. 

 VIII., No. 2, issued August 29, contains the 



