APPENDIX I. 



NOTICES OF BOOKS. 



The Cambridge Natural History, vol. v., " Peripatus," by Adam Sedgwick ; " Myria- 

 pods," by F. G. Sinclair; "Insects," by D. Sharp. 8vo, pp. xi. and 584. London: 

 Macmillan & Co., 1895. 



We were told in the prospectus that " The Cambridge Natural History is intended, in the 

 first instance, for those who have had no special scientific training, and who are not necessarily 

 acquainted with scientific language". Mr. Sedgwick's chapter on Peripatus in the present 

 volume gives a very curious interpretation to this intention. This chapter is, to a large extent, 

 written in language which is nothing if not scientific, and which, however clear and intelligible 

 to the well-versed student, must, at times, be completely mystifying to the untutored. 

 Except in a few pages, where in simple words he describes the living Peripatus and its habits 

 and external features, the style of his writing is much better suited to a scientific monograph 

 or a text-book of comparative zoology. Here is a sample of it, taken from the section 

 on development "The segmentation is peculiar, and leads to the formation of a solid 

 gastrula, composed of a cortex of ectodermal nuclei surrounding a central endodermal mass, 

 which consists of a much-vacuolated tissue with some irregularly shaped nuclei. The endo- 

 derm mass is exposed at one point — the blastopore (gastrula mouth). The central vacuoles 

 of the endoderm now unite and form the enteron of the embryo." The anatomy of Peri 

 patus is somewhat similarly treated of in another section. These two sections, the most 

 important in the chapter, will, no doubt, give pleasure to those readers who already possess 

 some knowledge of the subjects, and to those who do not they may prove an incentive to go 

 through a course of special training. Some excellent figures are scattered through the chapter, 

 and there is a map to show the geographical distribution of the genus. A list of species, with 

 their localities, is appended, and some of the species are briefly characterised. This list, or 

 synopsis as it is called, may be useful to some readers, but for the systematic student it will 

 have little value, as Mr. Sedgwick has apparently not taken the trouble to bring it up to date, 

 and it differs in no essential respect, so far as we can judge, from one which he published with 

 his monograph several years ago. 



Mr. Sinclair tells us in his chapter on the Myriapods that he " only aims at giving an 

 outline sketch of the group that shall be intelligible to the general reader who has not made a 

 special study of such matters ". In this aim he has, to some extent, succeeded very well. But 

 this is not all that we were led to expect. For did not the prospectus also say that "an 

 attempt would be made, not only to combine popular treatment with the latest results of 

 scientific research, but to make the volumes useful to those who may be regarded as serious 

 students of the various subjects"? We do not wish to imply that Mr. Sinclair has not made 

 such an attempt. Evidence of it is in fact to be found in those parts of the chapter in which 

 he writes on subjects with which his own researches have been particularly associated, but we 

 find very few traces of it elsewhere. His general introduction, in which he speaks of the habits 

 of Myriapods, is good, and his account of the itructure and development of some of the 

 groups leaves nothing to be desired. But when we turn to his treatment of classification and 

 his account of some of the smaller but not less interesting orders there is a different tale to tell. 

 Mr. Sinclair is apparently unaware that the whole subject of the classification of Myriapods 

 has in recent years been completely revised, and his own attempt at classification is a mere 

 revival of the antiquated system of Koch, with the addition of the two orders Symphyla and 

 Pauropoda. Pocock and Kingsley, to mention two only of the chief authorities, will scarcely 

 feel flattered to find that there is not the slightest reference to their views published several 

 years ago, and not yet so far as we know disputed, that the so-called Myriapods do not con- 

 stitute a single homogeneous class but consist of least two very distinct groups. We do not 

 feel competent to follow Mr. Sinclair through his detailed accounts of the different orders, but 

 if his treatment of the Symphyla may be taken as a sample of the rest, his performance in this 

 respect is very poor indeed. Scolopendrella, the sole genus of this order, shows certain points 

 of resemblance to the Thysanura, and is by some considered to be the living type which comes 

 nearest to the ancestral forms of both Myriapods and Insects. Mr. Sinclair very properly calls 



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