NATURE 



[March 3, 1910 



further, that many substances, which have been mis- 

 taken for chromatin on account of their affinity for 

 stains, are in reality reserve materials, precipitation- 

 products, and the like, and that this confusion of 

 chromatin with other substances has often led to the 

 erroneous distinction of two kinds of chromatin. 



In discussinp^ the theoretical aspects of reproduction 

 and fertilisation, the author states and reviews in a 

 very clear and interesting manner the various theories 

 that have been put forward, especially those of 

 W'eismann, Butschli, Hertwig', and Schaudinn, and 

 ends by sketching in brief outline a theory of his own. 

 Living cells are regarded as consisting principally of 

 two groups of vitally-active substances, the one, more 

 fluid, responsible for motor phenomena, the other, 

 more viscid, regulating metabolic cell-functions. In 

 cell-reproduction by fission these substances are never 

 distributed with mathematical equality amongst th'e 

 descendants, hence continued division brings about 

 accumulations of different properties in certain indi- 

 viduals, with, as a consequence, impaired vital 

 -activity and reproductive power. Individuals are pro- 

 duced, some of which become richer in reserve material 

 •(.emale), others in motile substance (male). Since 

 these two kinds of individuals contain aggregations of 

 substances which have intense mutual chemical re- 

 -actions, they exert an attraction one towards the 

 ■other; the two individuals tend to unite as gametes, 

 and by their union cell-equilibrium is restored and 

 vital powers renewed. Hence fertilisation is regarded 

 -;is a necessity for the life-cycle, due primarily to the 

 imperfections of cell-division and to the consequent 

 •Joss of equilibrium in the cell-constituents, a view 

 which unites and extends the theories of Schaudinn 

 and Hertwig respectively. 



The section dealing with the bionomics of the Pro- 

 tozoa is divided into the following subsections : — 

 • occurrence and distribution, habit and mode of life, 

 adaptation of the methods of nutrition, adaptations 

 of the reproductive processes and means of dispersal, 

 influence of the medium, light and rays, temperature 

 and climate. Under the heading " System," the 

 various classifications that have been put forward are 

 discussed. The Protozoa are classified into two main 

 divisions, first, the Plasmodroma, including the Rhizo- 

 ipoda, Mastigophora, and Sporozoa ; and, secondly, the 

 Ciliophora, including the Ciliata and Suctoria. The 

 Spirochaetes are regarded as leading from the or- 

 ganisms of bacterial nature to Mastigophora, and 

 hence, for the first time, we believe, in a treatise on 

 Protozoa, the Mastigophora are dealt with before the 

 Rhizopoda. 



The section on technique is a brief summary of 

 methods of cultivating, investigating, and preserving 

 Protozoa. 



The special part of the work is a detailed descrip- 

 tion, in systematic order, of the structure and life- 

 histories of the orders, families, and more important 

 genera and species of Protozoa. Intercalated amongst 

 the systematic descriptions are sections dealing with 

 the parasitic and pathogenic importance of certain 

 groups, namely, the Spirochaetes, Flagellates, 

 Am.oebae, and Telosporidia. In these sections the 

 diseases produced by the Protozoa in question, and 

 SO. 2105, VOL. 8-5] 



their pathology and etiology, are discussed, with 

 figures and descriptions of the blood-sucking inverte- 

 brates which are responsible for their dissemination. 

 From all this wealth of material we must be conteni 

 to note a few points concerning debated questions. 

 The theory of an alternation of sexual and non- 

 sexual generations in trypanosomes, comparable totl. 

 alternating cycles of Haemosporidia, is regarded ;> 

 purely hypothetical and in need of proof. The author 

 considers that it will probably be necessary in the 

 future to place the genus Trypanosoma in the family 

 Cercomonadidae, in close proximity to Herpetomona^ 

 and Crithidia; on the other hand, Trypanoplasma i- 

 placed in a separate family, Bodonidae. Schaudinn 's 

 statements with regard to the i'elationship of Trypano- 

 soma lo Hoemoproteus and Leucocytozoon are set forth 

 in detail, together with the criticisms and objections 

 of Novy, MacNeal, and others ; judgment is suspended 

 until more exact information shall have been obtained, 

 but Hartmann's union of Haemosporidia and Trypano- 

 somes into one group, the Binucleata, is not accepted. 

 The genus Haemoproteus (Halteridium) is dealt with 

 in an appendix to the Haemosporidia, together with 

 Babesia, Endotrypanum, and Leishmania ; it will ba 

 a surprise to most protozoologists to meet with Leish- 

 mania in this company, and we are decidedly of 

 opinion that its proper position is in the neighbour- j 

 hood of Herpetomonas. 



In the class Rhizopoda the forms with lobose pseu^ 

 dopodia and a shell are placed with the monothala- 

 mous Foraminifera, so that this order can no longer 

 be defined by the reticulose nature of its pseudopodia. 

 The Protomjxidea, including the genera Vampyrella, 

 Pseudospora, Chlamydomyxa, and Labyrinthula, are 

 placed as an appendix of uncertain position at the 

 end of the Rhizopoda. 



The Telosporidia are subdivided into Gregarinidae 

 and Coccidiomorpha ; the second of these divisions in- 

 cludes the Coccidia and the Haemosporidia, which are 

 divided into Plasmodidae and Haemogregarinida?. 

 We regret to see the familiar generic name C.occidium 

 replaced by Eimeria ; this is one of those many cases 

 where, in our opinion, rebellion against the law of 

 priority in nomenclature is not only lawful but impera- 

 tive. 



The feeling aroused by even a cursory scrutiny of 

 this book is one of dismay at the vast extent to which 

 the subject has grown, astonishment at the erudition 

 of the author, and gratitude to him for his pains- 

 taking diligence in putting together such a store of 

 important facts and so useful a guide to the intrica- 

 cies of the subject. It v^ould not be difficult, perhaps, 

 to point out parts of the book here and there in 

 which certain subjects or groups have not been so 

 well treated as others ; the Haemogregarines, for 

 instance, are not dealt with very adequatelv. But a 

 treatise of this size, on which the carping critic would 

 be perforce silent, could hardly have been written b 

 a human being, or even by several. It is seldom tha; 

 so great a work is completed by one man at the pre- 

 sent time. A striking feature of the book is the 

 number of beautiful illustrations, and especially of 

 previously unpublished figures, some by the author 

 and some by other investigators ; in particular we 



