NATURE 



[March 6, igi; 



The problems of the propagation and perpetua- 

 tion of races of organisms and the modes of trans- 

 ference of the parasitic forms are both of great 

 interest and of economic importance. The para- 

 sites have multiplicative methods of reproduction 

 which are necessary for the increase of their 

 numbers within one host, while propagative forms 

 are produced for their transference to other hosts. 

 The function of syngamy (fusion of gametes) as 

 a factor in keeping the tendency to variation 

 within the specific limits is a view worthy of more 

 attention. The many forms assumed by one 

 organism (polymorphism) are traced as arising 

 from adaptation to environment, to growth and 

 development, and to sexual differentiation. The 

 general part of the book closes with an interesting 

 chapter dealing with the vital physiological pheno- 

 mena shown by Protozoa. 



Following the general consideration of the 

 Protozoa, eight chapters are devoted to an account 

 of their systematic grouping, and the enormous 

 extent of the group can be realised by scanning 

 the sequence of genera or by referring to the 

 copious index. Prof. Minchin considers that two 

 types of organisation prevail among the Protozoa. 

 The simpler or Sarcodine type possesses no per- 

 manent locomotor organs when mature, although 

 such may be present in its youth form. The 

 second or Mastigophoran type, comprising 

 organisms often of small size, has permanent 

 locomotor organs, flagella, which are lost in the 

 resting phases. Subdivisions of each group are 

 numerous. The very diverse organisms among 

 the Rhizopoda, such as the Amoeba;, the sun- 

 animalcules (Helizoa), the chalk and ooze-formers 

 known as Foraminifera and Radiolaria, and the 

 Mycetozoa (claimed also by the botanist as the 

 slime fungi or Myxomycetes), are all considered. 

 Perhaps some newer illustrations would be an 

 improvement here. 



The bionomics of the flagellates are of much 

 interest, whether the parasitic forms or the tiny 

 inhabitants of ponds (also claimed by the botanist 

 as Algae) are under discussion. The interest of 

 the medical man will be claimed by the accounts 

 of the sleeping-sickness parasites, and the causes 

 of such diseases as kala-azar, oriental sore, and 

 malaria. The agriculturist should be interested 

 in the parasites of red-water and East Coast fever, 

 so fatal to cattle, as well as in the accounts of 

 Coccidia, fish tumours, and silkworm disease. 

 Incidentally, it may be mentioned that Prof. 

 Minchin does not now accept the results of 

 Schaudinn's researches on the parasites of the 

 little owl. 



Certain organisms, considered by some as 

 doubtfully Protozoa, such as the Spirochetes, 

 NO. 2262, VOL. 91] 



causing African tick fever and relapsing fever, 

 and the bodies responsible for small-pox, are 

 briefly considered in the concluding chapter. 

 Those who care for possible genealogies and 

 speculations will also find here an account of the 

 possible evolution and ancestry of the Protozoa. 



In conclusion, it is a pity that certain blemishes 

 in the form of loose statements, some inconsist- 

 encies of nomenclature (for example, the use of 

 Coccidium, Piroplasma), and slightly partisan 

 views on some contentious subjects have been 

 allowed to creep in and mar the book, but doubt- 

 less these will disappear in the second edition. 

 We would also suggest that an increase in the 

 number of illustrations would be a very great 

 advantage, and this should not be incommen- 

 surate with the cost of the book (215. net). 

 Some rather old figures could be replaced 

 by others embodying the results of more 

 recent and accepted research. Criticisms of 

 technique employed some years ago are obviously 

 futile, inasmuch as the said technique was the best 

 available at the time. Also we are distinctly of 

 opinion that the systematic part of the book 

 should be enlarged. But it must be recognised 

 that the task before Prof. Minchin was an 

 enormous one, and he is to be congratulated on 

 the successful issue of the work. 



CHEMISTRY AND ITS APPLICATIONS. 

 A Dictionary of Applied Chemistry. Revised and 

 enlarged edition. By Sir Edward Thorpe, C.B., 

 F.R.S., assisted by eminent contributors. 

 Vol. ii. Pp. viii + 786. Vol. iii. Pp. viii- 

 789. (London: Longmans, Green and Co., 

 1912.) Price 45s. net per volume. 



AS a notice of the first volume of the new- 

 edition of Thorpe's Dictionary appeared 

 in the columns of Nature for April 18, 1912, it 

 is not necessary on the present occasion to do 

 more than express cordial concurrence in the 

 reviewer's high estimate of the character of the 

 work and of the services rendered to the chemical 

 world by the editor and his staff of contributors. 

 In the two volumes before us the reader rather 

 naturally turns first to those articles which 

 specially illustrate the applications of science to 

 industry, namely, those of which the subjects had 

 not even come into practical existence at the date 

 of the former edition. Metallography, for example, 

 is one of these subjects, and is treated in a 

 thoroughly masterly manner by Dr. Walter 

 Rosenhain, of the National Physical Laboratory. 

 Here is a subject which, originating fifty years 

 ago in the microscopic study of rocks by Sorby, 

 has been largely dependent for the advances 



