484 



NATURE 



[June 



o» 



1910 



surroundings. An animal that is able to move about 

 can, within certain limits, choose its own immediate 

 surroundings, and is not, therefore, so much in need 

 of adaptability, but a sedentary animal or colony of 

 animals must either adapt itself to the surroundings 

 of the spot to which the larva happened to become 

 fixed or it must perish. The evidence that there is 

 really more than one variable species of Spongodes 

 does not appear to be at all conclusive, but it is at 

 any rate satisfactory to feel, when we contemplate the 

 results of Dr. Henderson's labours, that we have 

 some further knowledge of the varieties of form it 

 may assume. 



One word of protest may be said about the use 

 of the generic name Dendronephthya for Spongodes. 

 Whether the application of the strict rules of priority 

 justifies the change or not, and those who study the 

 literature of the genus may fairly claim that it does 

 not, the inconvenience and confusion which the change 

 of such an old and well-known generic name as 

 Spongodes introduces are quite sufficient justification 

 for our refusal to accept it. 



As might be expected in the description of a 

 shallow-water fauna, the number of new genera (four) 

 is very small. Of these the curious cup-like genus 

 Studeriotes, with its retractile polyparium, is the most 

 interesting. The new nephthyid Cactogorgia, with 

 its dense armour-plated walls of large spicules, is 

 a remarkable example of the extreme limits to which 

 spiculation in the Alcyonaria may be carried. 



The suggestion made by the authors that the genus 

 Chironephthya should be fused with Siphonogorgia 

 is clearly a move in the right direction. 



Among the many useful and valuable features of the 

 volume, attention may be specially directed to the sum- 

 mary of the characters of the pennatulid genus 

 Pteroeides. A hope may be expressed that before long 

 a similar summary of the genera and species of the 

 Juncellidae may be published. This family is evidently 

 under the consideration of the authors, but in the 

 present volume they have only given a tabular 

 statement of the specimens in the collection, without 

 assigning them to specific groups. The excellent 

 coloured plates and numerous illustrations in the text 

 add very materially to the volume, which is a very 

 noteworthy addition to our knowledge of the Alcyon- 

 aria. S. J. H. 



THE PHYSIOLOGY OF THE PROTOZOA. 

 Einfiihrung in die Physiologic der Einzelligen (Pro- 

 tozoen). By Dr. S. von Prowazek. Pp. v+172. 

 (Leipzig and Berlin : B. G. Teubner, 1910.) Price 

 6 marks. 



THIS work differs from all other treatises on the 

 growing subject of protozoology in being largely 

 devoted to the problems of function. It is a 

 condensed account of our present knowledge of this 

 highly important and difficult subject, and consists of 

 summaries of physiological results, often too short to 

 be easily intelligible, but of considerable value to that 

 increasing number of investigators who are interested 

 in recent advances in this field. The author is a well- 

 known and active worker, and does not hesitate to press 

 NO, 2 12 I, VOL. 83] 



certain views which have not as yet obtained com- 

 plete adherence. On the whole, however, he gives an 

 impartial view of the state of each problem so far as 

 the kaleidoscopic nature of the case allows. 



With regard to the question of protoplasmic struc- 

 ture, von Prowazek concludes that Biitschli's alveolar 

 theory does not account for all the facts. He holds 

 that protoplasm may be absolutely structureless, and 

 must, therefore, be regarded as polymorphic. Each 

 protozoan cell is, according to him, at least binuclear. 

 This view, though well known to be shared by Hart- 

 mann, is not generally accepted, and it would have 

 been advisable for more and better figures of the 

 nuclei of such common forms as those of amoeba to 

 have accompanied the statement, which, as it stands, 

 is not rendered quite convincing, though we are aware 

 of the evidence in its support. The functions of the 

 nucleus are dealt with at some length, and their dis- 

 cussion involves the consideration of much experi- 

 mental evidence ; in fact, it would be difficult to name 

 any function of the organism which is not assigned by 

 some writer to the activity of the nucleus. Form, 

 motion, enzymes, or at least proenzymes, respiration, 

 division, reproduction, heredity, regeneration, are all 

 more or less confidently assigned to this versatile 

 structure. Not onlv are its functional activities in- 

 creasingly stressed, but the importance of the nucleus 

 in originating structures hitherto supposed to be cyto- 

 plasmic is also fully considered. An interesting excep- 

 tion that is noted in this discussion is the fact that 

 amoebae can live for at least a month without a 

 nucleus, and a portion of a Stentor deprived of its 

 nucleus may reirenerate the lost parts of its body. 



Attention is directed to the importance of the mem- 

 brane that encloses the protozoan cell, and to the 

 mode whereby osmosis or absorption is performed. 

 The suggestion of Overton that the membrane con- 

 tains " lipoids " {e.g. lecithin and cholesterin), and that 

 these take an active part in the absorption of sub- 

 stances into the cell, is somewhat over-emphasised, 

 since it is by no means certain how far these "lipoids" 

 contribute to the formation of the ectoplasmic struc- 

 tures. At the same time, so much attention is now 

 being paid to this aspect of biochemistry that the 

 discussion is a very timely one and should lead to 

 further research. 



The latter half of the book is occupied by sum- 

 maries of what is known as to the functions and 

 " tropisms " of protozoa. With regard to respiration, 

 attention is directed to the natural or induced anaerobic 

 character of many ciliates as well as to the behaviour 

 of other infusoria when supplied with excess of 

 oxygen. Loeb's view that the presence of a nucleus 

 is essential to the oxidation of the cell is not upheld. 

 \n interesting account is given of the nutrition an4 

 movements of protozoa, but the behaviour of forms 

 such as amoeba, which contain chlorophyll corpuscles, 

 is almost entirely neglected, in spite of the work of 

 Grube and Doflein, and there is room for direiS 

 observation on the supposed ingestion of bacteria in 

 the case of many infusoria. W'ith regard to the 

 significance of fertilisation, the author concludes very^ 

 much in the sense of Doflein as given in his recent 



