November 22, 1901.] 



SCIENCE. 



809 



biological speculation. They have been and 

 will long continue to be the one group about 

 which cluster the numerous theories of bio- 

 genesis, the origin of the Metazoa, the origin 

 and significance of sex, heredity and death, the 

 dawn of consciousness and instinct and innu- 

 merable problems of lesser magnitude. Dr. 

 Calkins is to be congratulated on having worth- 

 ily overcome, or at any rate adroitly avoided, 

 many of the diflSculties of this task. At the 

 same time he has upheld the high standard of 

 scholarship set by the previous volumes in the 

 well-known * Biological Series. ' 



As Dr. Calkins infornas us in his preface, 

 "The subject-matter of the volume is treated 

 from three points of view : (1) The historical, 

 to which the first chapter is devoted. (2) The 

 comparative to which five chapters are given, 

 one to the group of Protozoa as a whole, the 

 other four to the main classes. (3) The gen- 

 eral, to which three chapters are devoted. 

 One of these is given to the phenomena of 

 old age or senile degeneration in Protozoa 

 and renewal of youth through the union of two 

 individuals, and to the bearing of these phe- 

 nomena upon sexual reproduction in general. 

 Another is given to the special structures of 

 nuclei and centrosomes of the Protozoa ; this, 

 the most technical chapter in the book, is in- 

 troduced because of the growing importance 

 which the Protozoa have in the problems of 

 cellular biology, especially with those dealing 

 with the origin of the division-center and its 

 accompanying structures in the cells of the 

 Metazoa. The last chapter is devoted to a con- 

 sideration of the physiology of the Protozoa, 

 with especial reference to the Protozoa as or- 

 ganisms endowed with the powers of coordina- 

 tion and of adaptation, which up to the present 

 time have eluded physical and chemical anal- 

 ysis." 



In pursuing this general plan the author has 

 consistently resisted the temptation of involv- 

 ing himself in undue detail, and it is evident 

 that he has everywhere striven to give proper 

 shape and proportions to his work. In some 

 parts of the volume, however, this brevity 

 almost borders on meagerness and obscurity. 

 The student who has long been irritated by the 

 unsatisfactory text book accounts of the life- 



histories of the Sporozoa will certainly wish 

 that Dr. Calkins had expanded his excellent 

 chapter on these organisms and introduced a 

 fuller account of recent works on the Gregar- 

 inida and Hsemosporidia. We miss, e. g., an 

 account of Apiosoma bigeminum, the source of 

 Texas fever, and its transfer by the cattle-tick 

 {BoopMlus bovis) in a manner analogous to the 

 transfer of Plasmodium malariss by the mosquito 

 (Anopheles). We should also have welcomed a 

 fuller treatment of the geographical distribu- 

 tion of the Protozoa in general, their modes of 

 dissemination and the phenomena of anabiosis. 



Many morphologists and physiologists will 

 wish that the author had dealt more critic- 

 ally with the conception of * rejuvenescence,' 

 a conception which smacks of ' Naturphi- 

 losophie ' and is at most only an anthropo- 

 morphic ' Photographie des Problems.' The 

 facts of parthenogenesis, both natural and arti- 

 ficial, appear flatly to contradict the assumption 

 of Maupas and others that the temporary or 

 permanent union of two exhausted cells results 

 in one or two rejuvenated ones. This view was 

 repudiated by Weismann on very good grounds 

 several years ago. 



The work of Calkins contains a classification 

 of the Protozoa carried out to the families and 

 genei'a. Unfortunately it is appended to three 

 separate chapters and printed in such a form as 

 to violate the very first rules of taxonomy. 

 Classes, sub-classes, orders and suborders are 

 all introduced in the same style of type and 

 the various groups are coordinated in such a 

 manner as to render a rapid and easy survey of 

 the classification difficult, if not impossible. 

 Taxonomy is the quintessence of our present 

 morphological knowledge, and it is time that the 

 prejudices of the narrow-gauge morphologist be 

 not still further fostered by negligence in tabu- 

 lating the essentials of the very science to which 

 he is devoting himself with the characteristic 

 myopia of one who sees not the forest because 

 he is studying the venation of its leaves. 



The volume is written throughout in a good, 

 orderly style. Words like ' mononucleate ' and 

 ' unshelled,' in the sense of * shell less ' are 

 conspicu'busly rare. The illustrations are clear, 

 though occasionally too coarse for representa- 

 tions of such minute organisms. This is very 



