738 



SCIENCE 



[N. S. Vol. XXVII. No. 697 



omitting even the heart or a ventral venous 

 trunk representing it. The other is compre- 

 hensive and complicated, yet omits the great 

 veins, dorsal and ventral, and even the aorta, 

 the only viscus in the transection besides the 

 enteron; in brief, the two sections are not 

 correlated. Finally, the spleen and the pan- 

 creas are so represented as to give the distinct 

 impression of a single continuous organ with 

 a hole at the smaller end. As in most works 

 of the kind, comparable figures are often re- 

 versed in direction. Without insisting unduly 

 upon conformity with the practise of the elder 

 Agassiz,^ for students such reversals are often 

 confusing, especially where difierent sets of 

 abbreviations are used for the same parts, as 

 in Figs. 149 and 150, 160 and 161, 172 and 

 173. 



In the introduction of sixteen pages, after 

 ■definitions and general considerations, verte- 

 brate ontogeny is outlined, all too briefly for 

 the student; indeed, only one already familiar 

 -with the facts would comprehend either the 

 •conversion of the blastula into the gastrula, 

 •or the formation of the notochord and neural 

 tube. And what impression would be made 

 upon the average reader as to the dependa- 

 bility of biologic science by the statement 

 (p. 5) that " In all vertebrates the blastophere 

 passes — or did so in earlier times — into," etc., 

 with no " probably " or corresponding German 

 word to indicate that, however well founded, 

 our belief is pure hypothesis, unproven and 

 unprovable? The "general classification of 

 the principal vertebrate groups," although 

 occupying more space than in the original, 

 and wiith two thirds of page 15 left blank, 

 absolutely ignores extinct forms, even some 

 that are discussed in the text, e. g., Archwop- 

 teryx (p. 60), Hesperornis and IcMhyornis 

 (123, 318), Stegocephali (142, 148), Pleura- 

 canthus (145), Ichthyosaurus and Plesiosaurus 

 (163). The introduction closes with a full- 

 page " Table Showing the Gradual Develop- 

 ment of the Vertebrata in Time." Like the 

 original, it is said to be "modified from H. 

 Credner," but there is no explanation of the 



* See American Association for the Advancement 

 of Science, Proceedings, 1873, p. 274. 



further changes, especially the inclusion of 

 the Amphibia and Reptilia in a single column. 



The statement on page 63 as to the persist- 

 ence of the human tail up to a certain embry- 

 onic size is undesirably condensed from the 

 original (p. 65) ; it lacks the two instructive 

 figures there given, and — like the original — 

 it fails to note the presence of a perfectly 

 distinct caudal appendage at a considerably 

 later stage, even though it may not contain 

 the original prolongations of the neural and 

 enteric cavities. The several kinds of tails 

 among fishes might well have received fuller 

 treatment. The figure of Protopterus in the 

 original is omitted from the adaptation, and 

 neither portrays a typical heterocercal tail 

 (sturgeons and most sharks), nor the very 

 instructive developmental stages of the gar 

 and some teleosts so fully made known by the 

 younger Agassiz thirty years ago. The ac- 

 count of the relations of the ovaries to the 

 oviducts in teleosts is not clear in the original 

 (p. 559), and still less so in the adaptation 

 (p. 466). 



Some of the following features may not 

 commend themselves to all, but they afford 

 the reviewer considerable gratification: The 

 distinct recognition of the importance of the 

 olfactory portion of the brain (pp. 200 

 and 220) ; the omission of the " Isthmus 

 rhombeneephali " from the encephalic seg- 

 ments; the retention of the correct spelling, 

 Lepidosteus; the use of coele and its com- 

 pounds for the cavities of the brain, and of 

 postcaval and precaval; and the avoidance of 

 " Anlage." 



The following statements as to the brain 

 are more or less defective, misleading or erro- 

 neous. 



Page 201 — " The middle commissure is pres- 

 ent in mammals only." It exists in the alli- 

 gator and in all turtles so far as the reviewer 

 is aware. The succeeding paragraph as to the 

 corrugations of the cerebral surface is worded 

 even more loosely than the original ; it implies 

 that only the lateral aspect is so modified and 

 that pallium and cortex are synonymous; fails 

 to distinguish between total and partial fis- 

 sures, and omits the concluding phrase of the 



