6i8 



NATURE 



[October 29, 1903 



all vectorial, that is, geometrical, and marked by great 

 clearness of exposition. Such a treatment of statics 

 forms a most need'ful corrective of the methods of a 

 purely "analytical statics," which has a strong 

 tendency to keep the subject aloof from reality, and to 

 obscure its physical nature. " One does not find 

 figures in this book," boasted Lagrange in his 

 ■*' M^canique Analytique," but the absence of geo- 

 tnetrical methods and conceptions is not to the advan- 

 tage of the subject. 



In the penultimate chapter Prof. Henrici gives a 

 short, very useful, and well explained account of the 

 reciprocal figures of graphic statics, and the last 

 chapter is a very short one on the deduction of the 

 elementary trigonometrical formulae from vector 

 methods. With all deference to the author, however, 

 it is to be feared that pupils will not, within time at 

 the earth's disposal, be so much accustomed to think 

 in vectors as to deduce their notions of a sine and a 

 cosine otherwise than by the old method. 



Next to the systematic teaching of the solution of 

 all kinds of equations by graphic constructions, the 

 wider employment of geometrical methods in dynamics 

 Is our greatest desideratum, and for this reason we 

 have to thank Prof, Henrici for this elegant little 

 treatise. George M. Minchin. 



THREE PROTOZOAN ARTICLES. 

 A Treatise on Zoology. Edited by E. Ray Lankester, 

 LL.D., F.R.S., &c. Part i. Introduction and 

 Protozoa. Second Fascicle. Pp. vi + 451. (London: 

 A. and C. Black, 1903.) Price 15s. net. 



THE erratic order in which the various volumes of 

 Prof. Lankester's treatise are appearing is, from 

 the nature of their subject, a matter of very little con- 

 sequence, and we are glad to welcome now this instal- 

 ment of the protozoan chapter. It is the second 

 fascicle of part i., of which the first fascicle, contain- 

 ing the introduction and the groups not here included, 

 has still to appear. The inconvenience of the intended 

 arrangement of parts is clearly demonstrated, and it 

 is very fortunate that it has not resulted in the deten- 

 tion at the press of the valuable essays which make up 

 this volume. A large part of the editor's difficulties 

 liave resulted, it is clear, from his adherence to the 

 plan of producing bound volumes of nearly uniform 

 size— in following, that is to say, the mode of publi- 

 cation of the recent " Cambridge Natural History " 

 and of other similar works of collaboration. We 

 believe it would prove to be in the interest of authors 

 and readers alike if no attempt were made by the 

 editors of series of this kind to produce periodically 

 completed volumes, and if the separate articles were 

 issued uniformly, but unbound, in the style of German 

 monographs. The total expense to the purchaser of 

 the whole series could remain the same by an obvious 

 arrangement, while the gain tO' many specialists would 

 be immense. We have a case in point in the present 

 volume. Prof. Minchin 's valuable monograph on the 

 Sporozoa occupies about one-half of the whole volume, 

 and might, we gather, have been already for some 

 time in our hands if it had appeared separately in paper 

 <5overs. Its subject is precisely one in which publica- 

 tion might well have been both early and individual 

 NO. 1774, VOL. 68] 



in the interests of the medical profession, for which it 

 has, perhaps, its chief importance at the present time. 

 The deliberate manufacture of volumes, as such, while 

 we can see nothing at all to recommend it, is exposed 

 at the same time to the serious objection of stimulating 

 over-production. The publication of a complete 

 "Cambridge Natural History," and now of what is 

 virtually an Oxford treatise, suggests inevitably that 

 among the whole body of English zoologists a good 

 deal of research has been recently sacrificed to text- 

 book writing, of which a large part, however conscien- 

 tious, has been redundant. 



We can say this now with the greater assurance, 

 because it cannot be taken as applying to the excellent 

 articles on the Foraminifera, the Sporozoa, the Ciliata, 

 and the Acinetaria in the present volume. The section 

 dealing with the Sporozoa, by Prof. Minchin, takes 

 its place as an admirable systematic account of the 

 group, prefaced by a general sketch of their characters 

 and of the typical life-history. The recent develop- 

 ments of our knowledge of sporozoan parasites in con- 

 nection with malarial disease give a special import- 

 ance, as we have said, to this monograph. Prof. 

 Minchin provides in his description of the Haemo- 

 sporidia exactly what is now becoming essential know- 

 ledge for the student of disease, and it is highly desir- 

 able, we think, that medical men should approach the 

 study of this group from a more general point of view 

 than that permitted in the restricted accounts of the 

 malaria parasite written specially for their use. In 

 the interests of further developments of curative and 

 preventive treatment in new directions, it is of the 

 first importance that the morphology and life-cycles 

 of the members of this group should be completely 

 determined, although, as the author claims, " the life- 

 cycle of the malarial parasite is now thoroughly known 

 in all its features." The recent work of Schaudinn, 

 who has explained the occurrence of relapse in malaria 

 without fresh infection as due to a kind of partheno- 

 genetic reproduction by resistant and long-lived macro- 

 gametocytes, is an example of the value in these 

 inquiries of a zoological outlook, and it is to be re- 

 membered that the " black spores " of Ross have not 

 yet been assigned with certainty to their place in a 

 life-cycle. With regard to the voluminously alleged 

 connection between the Sporozoa and cancer. Prof. 

 Minchin is content to express the hostility of most 

 zoologists, but he gives all the necessary material for 

 following the discussion elsewhere. In summing up 

 the affinities of the whole group he decides against the 

 theory of Euglenoid ancestry which Biitschli advanced, 

 and argues in favour of a descent from the Rhizopoda, 

 quoting the interesting example of parasitism which 

 Schewiakoff has found in simple amoeboid forms. He 

 concludes his article with a valuable compilation of 

 sporozoan hosts, including Labb^'s list with modern 

 additions, and an abundant bibliography is appended, 

 brought up to the beginning of the present year. It 

 would be difficult to suggest any Improvement in the 

 author's selection of illustrations or in their execution. 



Prof. Hickson, who has undertaken the Infusoria, 

 does not include the Flagellata, but deals only with the 

 Ciliata and Acinetaria, grouped as the Corticata 

 Heterokaryota. Here again we can have nothing 

 but praise for his admirably illustrated account of these 



