124 NATURAL SCIENCE. Feb.. 



the lately rediscovered Glomeridesnnts are not mentioned at all. The 

 Polydesmidae are said to have always nineteen body-segments ; most 

 of the genera have twenty. The Glomeridai and Sphaerotheriidbe are 

 credited with eleven and twelve body-segments respectively ; in each 

 case one too few. Not a word directs attention to the peculiar suctorial 

 mouth oi Polyzonmm; and the openings "near the lateral corners of 

 the body-rings" in that animal are not stigmata but stink-holes. 

 Turning to the centipedes, we are told that the Lithobiidse have 

 " many eyes " ; Henicobs has but one ocellus on each side. Clawed 

 anal legs are given as a family character of the Geophilidat' ; in several 

 Geophili these limbs have no claws. The dorsal plates of Scutigeva 

 are said to be smaller than the ventrals ; they are always larger, as 

 Mr. Sinclair must surely know from his own studies on the animal. 

 Haase's interesting genus Cerinatohins (forming a distinct family) is, of 

 course, not mentioned at all. If Mr. Sinclair had taken the trouble 

 to find out the existence of this intermediate form between the 

 Lithobiid^e and Scntigera, he would perhaps have hesitated to raise the 

 latter genus to ordinal rank ; equal in importance to the Chilopoda, 

 Diplopoda, Symphyla, and Pauropoda. But it is really astounding 

 that a chapter on Myriapoda, in a Avork professing to give the latest 

 results of research, should contain no reference to the view — several 

 years old, and independently advocated by Pocock and Kingsley — 

 that the association of these groups in a single class is unnatural, and 

 that the Chilopoda and their allies are closer to the Insecta than to 

 the Diplopoda. Suppose this chapter had been entrusted to a 

 classifier, who, considering it necessary to put in something about 

 development, might have written that, " without desiring to under- 

 value the work of several recent investigators, he thought it better to 

 summarise Newport and Metschnikoff"'s accounts of myriapod em- 

 bryology " : such treatment of the subject would appear incomplete 

 and one-sided to Mr. Sinclair, yet he has treated the systematic aspect 

 of the group in a manner precisely analogous. It is, of course, a mere 

 truism that embryological and systematic work are alike necessary 

 for the progress of zoology, and that the workers in either branch 

 should feel the unity of aim underlying their diverse labours ; but 

 such a chapter as this shows that there may still be need of exhortation 

 to naturalists to take an intelligent interest in each other's subjects. 



The classificatory section is followed by an account of the 

 structure of myriapods. This is well and clearly written, and the 

 author evidently remembers that his task is to instruct the unlearned 

 as well as to guide the serious student. Indeed, the latter might 

 complain that from his point of view some features are passed over 

 too briefly. Even here errors are not wanting : all millipedes, except 

 the Polyxenidae, are said to possess stink-glands ; the Chordeumida? 

 have none. More space might have been devoted to such very 

 interesting and problematical forms as ScolopendrcUa and Pauvopns 

 and figures of these should certainly have been given. The illustra- 

 tions of entire animals are all from Koch, and the Scutigeva wants 

 several pairs of legs, though no comment is made as to its imperfection. 

 The structural figures are after Latzel, copied from Mr. Sinclair's own 

 papers, or original. 



The only fault that might be found with the section on the de- 

 velopment of myriapods is that it is drawn too exclusively from 

 Mr. Sinclair's own researches. It consequently neglects the centi- 

 pedes ; but it is an excellent summary of diplopod development, and 

 serves admirably the twofold purpose claimed for the book. Mr. 

 Sinclair shows how embryology can be made attractive to the general 



