Mabch 25, 1910] 



SCIENCE 



457 



Pp. X + 914, mit 825 Abbildungen im Text. 



Jena, Gustav Fisciier. 1909. M. 24, Geb. 



26.50. 



The rapid development in recent years of 

 the science of protozoology to a position co- 

 ordinate with bacteriology is reflected in the 

 enormous increase in the literature dealing 

 with the Protozoa. IllLie Archiv fur Protisten- 

 Tcunde founded by Schaudinn in 1902 is now 

 in its eighteenth volume. For the year 1890 

 the Zoological Record lists 109 titles under 

 protozoa, for 1900 there are 167, and 1905 no 

 less than 522, the high-water mark to date. 



This activity in research has not only 

 brought to light countless details of structure, 

 and increased many fold the categories of life- 

 histories, but it has also complicated rather 

 than simplified our general notions regarding 

 the cytology of protists and the primitive 

 processes of reproduction. The Protozoa are 

 no longer to be regarded as simple organisms. 

 It has likewise raised many hotly contested 

 questions such as the life history and rela- 

 tionships of the trypanosomes, the relation- 

 ships of the spirochsetes and the occurrence 

 and meaning of chromidia. It has brought to 

 light not a few problematical protists, seen 

 for example in those structures associated 

 with such diseases as small-pox, measles, scar- 

 let fever, epithelioma contagiosum and tra- 

 choma which Prowazek has grouped together 

 as Chlamydozoa, as well as other less notorious 

 organisms which are with difficulty allocated 

 in existing categories, though beyond all 

 question to be regarded as protozoa. 



The stupendous task of assembling, coordi- 

 nating and sifting this ever-increasing flood of 

 protozoological literature into a " Lehrbuch " 

 would be attempted only by a German, and 

 even Dr. Doflein admits that he would not 

 have undertaken the three years' " miihsamer 

 Arbeit " had he clearly foreseen the magni- 

 tude of the task and the burden of reviewing 

 the literature. 



The author's treatment of this overwhelm- 

 ing mass of data has been facilitated by his 

 own incursions into the different fields of re- 

 search here represented. His treatment of 

 contested points is wisely conservative and 



objective, though one is disappointed in not 

 finding a full and critical discussion of the 

 claims of the Chlamydozoa for admission to 

 the category of protozoan organisms and re- 

 grets their summary dismissal. 



The account of the sexual reproduction of 

 Trypanosoma levjisi in the rat louse as de- 

 scribed by Prowazek is regarded by Doflein as 

 hypothetical throughout, resting upon too few 

 observations, and these apparently upon ab- 

 normal stages. It remains to be seen if later 

 work will not confirm the existence of a sexual 

 cycle in an insect host. Schaudinn's account 

 of the complicated life histories of the blood 

 parasites of the owl is, perhaps more justly, 

 dismissed as improbable in the light of the 

 work of Novy and his collaborators. 



The point of view from which the book is 

 written is most commendable, to wit, to bring 

 the results of investigations upon parasitic 

 and pathogenic protozoa into correlation with 

 our general knowledge of the natural history 

 of the group. While the parasitic protozoa 

 are given a large place in the systematic part 

 of the text even to the exclusion of others 

 equally interesting and important but non- 

 pathogenic, the main outlines of the work and 

 the general discussions are not thus limited 

 but are conceived and elaborated along the 

 broadest lines so that the work is of value to 

 all who deal with protozoa or with the biolog- 

 ical problems which they may elucidate. 



The introductory treatment of the general 

 morphology, physiology, reproduction and 

 ecology of the groups forms the first third of 

 the volume, while the remainder contains a 

 systematic presentation of the phylum proto- 

 zoa by orders and families carried to genera 

 and species in many cases of important para- 

 sitic and pathogenic forms. Special chapters 

 on the parasitism and pathological significance 

 of the different groups are interspersed in this 

 section. 



The Flagellata are treated in 142 pages, the 

 Rhizopoda in 132, the Sporozoa in 218 and the 

 Ciliata in 47. With all due regard to the sci- 

 entific, economic and social value of the 

 pathogenic phase of protozoology, to the limi- 

 tations of a single volume, to the relative de- 



