1898] SOME NEW BOOKS 203 



\knows the fact, peculiar as it is, that the nephrostome of Chaetopods 

 is always in the segment preceding that of the pore — though the sig- 

 nificance of this arrangement is unknown. These are samples of 

 sundry errors; and others of less note occur in the descriptions of 

 some of tlie types. If definite examples are taken to illustrate the 

 structure of the group, it appears to us that every statement in con- 

 nection with them should be as accurate as dissection and careful 

 observation can make them. Some of the errors will be discovered by 

 any student who dissects the type with any care at all. Also, we fail 

 to see why the nephridium of the type (Zumbricus) is illustrated hj a 

 figure of that organ of Tubifcx ; it would have been quite as easy to 

 borrow the block of Gegenbauer's figure of the earthworm nephridium, 

 as that of Lang's. 



()n p. 569, the statement occurs that "in Scvtigera one of the 

 stigmata is unpaired and dorsal " ; the fact is that in this Chilopod, 

 they all have this position ; no mention is made of the peculiar organ 

 into which they lead. On p. 612, the abdomen oi Limulus is said to 

 consist of "seven firmly united segments." On p. 627, it contains 

 " only eight segments " ; but Lankester showed years ago that the alido- 

 men consists of twelve fused segments. 



In vol. ii., pp. 137 and 158, we read that the vertebrae of Sela- 

 cliians contain " bone " ; this is a bad error, since calcified fi1)ro-carti- 

 lage is meant, which is not the same thing as bone, either histologi- 

 cally, chemically or developmentally. 



We have referred to the abundance and general excellence of the 

 illustrations, but it seems strange that it is necessary to illustrate 

 AjJteryx by a photograph of a stuffed specimen in the Museum 

 of the Eoyal College of Surgeons, London. The picture of the 

 egg of Callorhynchus, with the embryo within, is especially good, and 

 we are glad to see those of foetal marsupials with the embryonic 

 membranes ; there are good ones of Aurelia, Sponge anatomy ; but one 

 featue of the pictures is the diagrammatic dissection or solid section, 

 e.fj. of Amphioxus ; the ideal vertebrate is also a striking picture. 



But some err in the attempt to show too much ; two or more less 

 elaborate figures would have been clearer. Thus, the dissection of 

 the Leech, fig. 373, does not give a true idea of the alimentary canal, 

 since among other things tlie coeca are represented both in a state of 

 distension and of contraction on the same side, and there is a figure 

 (33<S) of seven bristles of different Polychaeta without any indication, 

 anywhere, as to what genus each bristle represents. Some figures are 

 attributed to wrong authors, or the author is not mentioned ; thus fig. 

 269 is by Van Bemmelen, and fig. 259 by Allmann, fig. 165 is l)y 

 Julin — these names are not mentioned. 



An inexplicable error occurs on p. 188, vol. i. Fig. 137 is Lacaze 

 Duthiers' well-known picture of the Eed Coral, but it is described as 

 '^ Girripatlies an(juinca" (after Bronn). A curious transposition of 

 the legends of two phylogenies occurs on pp. 580, 582 of vol. ii. 



It is a notoriously difficult task for one, or even two, men to w^rite 

 a Text-Book which shall be free from ei'rors, and satisfy the various 

 s])ecialists who may have to review it, for each is apt to consider his 

 •particular group as the group that should be properly done. 

 The present book is no exception. Nevertheless, in spite of 



