152 



NA TURE 



[December 9, 1909 



ideas. Bacon's aphorism, "Truth more easily 

 comes out of error than out of confusion," may 

 be applioci to any honest attempt to express progress 

 in knowledge by a re-adjustment of existing classifi- 

 cations. These words may seem to imply a disin- 

 clination to accept the views embodied in Dr. Scott's 

 classification ; they are quoted rather as an expres- 

 sion of gratitude for a contribution the value of which 

 is to be measured, not by considerations of finality, but 

 by the stimulus which it gives to wholesome criticism 

 and to a broader survey of the facts at our disposal. 



By the expansion of the " Studies," Dr. Scott has 

 given a further incentive to students of plant evolu- 

 tion, and has produced a book which, in clearness 

 of exposition, in scientific accuracy, and in sound- 

 ness of judgment, it would be difficult to surpass. 



A. C. Seward. 



PISCIXE MORPHOLOGY. 

 A Treatise on Zoology. Edited by Sir Ray Lankester, 

 K.C.B., F.R.S. Part IX., Vcrtebrata Craniata. 

 First Fascicle, Cyclostomes and Fishes. By E. S. 

 Goodrich, F.R.S. Pp. xvi + 518. (London: A. and 

 C. Black, 1909.) Price 20s. net. 



BOTH the author of this book and the editor of 

 the " Treatise on Zoology " are to be congratu- 

 lated on this, the latest addition to the series. The 

 author is dealing with a subject with which he is 

 thoroughly familiar, and to which he has contributed 

 a large amount of important research. The whole 

 plan of the book is carefully conceived and carried 

 •out, and we can only regret that the necessity to keep 

 the size of the book within certain limits has made 

 great concentration inevitable in dealing with many 

 parts of the subject. However, references to more than 

 five hundred original papers afford a guide to the 

 student who wishes to amplify Mr. Goodrich's text. 



This book is less a mere compilation than are most 

 text-books, and the personality of the author is con- 

 stantly felt. One of the chief features is the great 

 number of excellent new figures, largely semi- 

 diagrammatic representations of dissections, showing 

 the three dimensions of space. Readers will be 

 deeply grateful for this, for we have all experienced 

 the annoyance of turning up text-book after text-book 

 in the attempt to clear up some doubtful point, and 

 finding the same figure, taken from some time- 

 honoured authority, reproduced in all. How little the 

 book before us suffers from this common failing is 

 evident when it is said that more than a hundred and 

 fifty of the figures are of the author's own drawing. 



The subject is considered from a purely morpho- 

 logical and evolutionary point of view, to the almost 

 complete exclusion of the physiological side, and the 

 references to function are extremely few. While it is 

 necessary in a book of limited length to discriminate 

 between what to put in and what to leave out, one 

 feels, perhaps, that in this case the fact that organs 

 are functional parts of living animals has been kept 

 too much in the background. 



It is natural, and also desirable, that an author 

 should treat at most length those parts of his subject 

 to which he himself has given most attention, even 

 NO. 2093, VOL. 82] 



at the expense of other portions. Here, many of the 

 " soft-parts," for example, the nervous system, and 

 the digestive organs receive rather scant attention. 

 On the other hand, the supporting tissues, especially 

 the exoskeleton and the skeleton of the median and 

 paired fins, are admirably treated, and at considerable 

 length. 



The classification adopted differs in many respects 

 from that found in contemporary text-books. The 

 Pisces are divided into three great groups, the 

 Chondricthyes, Ostracodermi, and Osteichthyes. The 

 Chondricthyes include the Elasmobranchii (Selachii 

 and Holocephali) and the extinct groups usually 

 associated with them. The Osteichthyes are divided 

 into two groups, the first including the Dipnoi and 

 Coccosteomorphi, the second the Teleostomi. Useful 

 phylogenetic trees are given at the beginning of the 

 larger groups. In dealing with the Teleostei, use is 

 freely made of subdivisions represented only by letters 

 or numerals, thus saving the coining of new words — 

 a most desirable proceeding in dealing with a pro- 

 visional classification, such as that of the Teleosteans 

 must at present be. 



.\ few special points of minor importance call for 

 criticism. On p. 11 we read that 



" Stohr showed that, in the Urodela, the 'vertebral 

 region ' is developed from three distinct centres — the 

 parachordal, the mesotic cartilage of the auditory 

 capsule, and an occipital segment resembling .a 

 vertebra." 



This is a very confusing use of the terms, neither 

 in accordance with Stohr's original usage nor with 

 that commonly accepted at present. Stohr divided the 

 post-trabecular elements of the skull into three, the 

 " Balkenplatte," mesotic cartilage, and occipital 

 portion, and identified the last of these with Huxley's 

 parachordals. The custom now is to use the word 

 parachordal as including all these three sections. The 

 student will have difficulty in reconciling Mr. 

 Goodrich's use of the term with either of the other 

 two meanings. 



On p. 116 we read, as one of the primitive char- 

 acters of the Pisces (which group here does not 

 include the Cyclostomes), that the pericardium may 

 communicate with the abdominal coclome. In view 

 of the f.act that this communication in Elasmobranchs 

 is formed secondarily in ontogeny after the two 

 cavities have been completely separated from each 

 other, it would have been better not to have included 

 it in the list of characters "considered primitive" 

 without a qualifying note. 



"Occipital " (p. 239) hardly seems a happy name for 

 the large dermal bone of the Dipnoi (Wiedersheim's 

 fronto-parietal), which, indeed, roofs in the whole 

 cranium in the Dipneumona. 



Considering tlie book as a whole, we may say con- 

 fidently that, in spite of the niunber of excellent text- 

 books already available, Mr^ Goodrich's work will be 

 extremely welcome to the student of vertebrate 

 morphology, as being both a trustworthy source of 

 general information on the subject and in many 

 points an epitome of recent research by one who has 

 himself taken a most important part in it. 



W. E. A. 



