1909 Reviews. g5 



AuioLig the best known of the Protozoa undoubtedly are the Lobosa. 

 Formerly of purely systematic interest, it has now been amph' demon- 

 strated that their study has led to the recognition of the cause of 

 several obscure forms of disease. E/idaniaba /lislo/iia. for example, so like 

 E. coli in size and form, yet so different in its life-history, is known to 

 be the active cause of tropical dysentery. Prof. Hickson has made this 

 section one of the most interesting parts of the volume. 



The pelagic marine Radiolaria are of less practical interest, except 

 that they form an important element in the constitution of some of our 

 rocks. Yet only now and tJien is a stray specimen recorded from our 

 coasts. Dr. Gamble, the author of this section, alludes to the discoverv, 

 bv the ^Misses Delap, of Thalassicolla on the west coast of Ireland. 



Of all the groups classed as Protozoa in this volume the Mastigophora 

 are the most debatable. In the authors' opinion the controversy whether 

 such and such an order of INIastigophora should be reckoned among the 

 unicellular Algte or among the Protozoa is now practically over, and 

 they hold that Vjiological disquisitions upon the group are equally at 

 home and equally necessary in zoological antl botanical treatises. The 

 various sub-classes of this group are discus.'^ed by Mr. Willey and Prof. 

 Hickson, except one, the parasitic Lissoflagellata. which has been 

 considered worthy of more detailed treatment. 



The unstability of the classification of these organisms is well illus- 

 trated b3-the fact that the arrangement of the Lissoflagellata as adopted 

 by Dr. Woodcock, differs considerably from that proposed by Messrs. 

 Willey and Hickson in the earlier part of the same section. Popularl}- 

 known as '' Trypanosomes," these parasitic Protozoa are of the greatest 

 interest and of extreme economic importance. Inhabiting chiefly the 

 blood of vertebrates, they seem to produce various symptoms resulting 

 in the serious illness or death of the host. Thus "surra,'" an Indian 

 horse disease, the ' tsetse-fly disease "' of African cattle and horses, and 

 finally the terrible ''sleeping sickness" of man are all proved to be due 

 to various Trypanosomes. To Dr. Woodcock's ver\' able account of 

 these organisms is appended a list of all the known natural hosts of 

 Trypanosomes and allied forms, which will be useful to students. 



R. P. vS. 



A LITTLE MOSS BOOK. 



British IVlosses. By TiiK Right Hon. vSir Kdward Pry, G.C.B. 

 2ud edition. London : Witherby & Co., 190S. pp. 72. \s. 6d. net. 



This little work, as the author explains in the preface, grew out of a 

 lecture on British Mosses delivered in 1891 at the British Institution. 

 While covering much the same ground, the 2nd edition now before us 

 has been improved by the omission of the HepaticLC, which were 

 referred to very briefly in the ist edition published in 1892. 



The author first describes the life-history of a moss with the aid of 

 excellent diagrams and illustrations, and treats of the structure of the 

 Gametophyte and Sporophyte in some detail. 



