424 NATURAL SCIENCE [December 



selected types, but rather to show the relationships of animals and 

 thus to manifest evolution in the Animal Kingdom. As the chief 

 guide in determining those relationships, Prof. Eoule takes em- 

 bryology, although palaeontology and comparative morphology and 

 histology are not rejected. 



The Animal Kingdom is divided into sixteen branches, dealt with 

 in the following order : Sarcodic Protozoa, Ciliate Protozoa, Mesozoa, 

 Spongida, Hydrozoa, Scyphozoa, Plathelminthes, Nemathelminthes, 

 Trochozoa (Botifera ; Bryozoa, Brachiopoda, Phorouidea, Sipunculidea ; 

 Mollusca ; Archiannelida, Hirudinea, Chaetopoda ; Pseudannelida = 

 Sternaspids & Echiurians), Arthropoda, Chaetognatha, Peripatida, 

 Echinoderma, Enteropneusta, Tunicata, Vertebrata. Each of these 

 branches is dealt with under the following heads : General considera- 

 tions and relations to other branches ; Distribution in nature ; General 

 organisation, first of the embryo, then of the adult ; Comparative 

 account of the different body systems, as manifested in the various 

 Classes of the Branch ; Principles of classification, division into Classes, 

 and mutual relations of the Classes ; Bibliography. The second 

 volume ends with two indices, the first to the zoological names, the 

 second to the anatomical terms. There is no general chapter dealing 

 with the Animal Kingdom as a whole, or with the classification 

 adopted, since that was given in the previous works referred to 

 above. 



Seeing that the subject is one of such obscurity, and open to so 

 wide diversity of opinion, it hardly seems worth while pointing out 

 the paths along which we should not care to follow our professorial 

 guide. That he has made the attempt, and that Messrs Masson have 

 published it, is alone a reason for gratitude. For the book, though 

 somewhat wordy, and occasionally less clear than we are accustomed 

 to from a Frenchman, furnishes a series of very readable accounts 

 with many suggestions of interest. Without casting any slur on 

 embryological research, we must confess to some distrust in those 

 who place quite as much reliance on it as does Prof. Eoule. But taking- 

 it at his valuation, we fail to see how it lends support to the view 

 that the Nautiloidea are ancestral to the Ammonoidea and the ad- 

 mittedly dibranchiate forms ; for their embryology shows clearly that 

 the Nautiloidea have lost an important structure, the protoconch, once 

 possessed by them and still possessed by the other orders. We also 

 venture to think that the known facts in the embryology of recent 

 echinoderms afford no proof whatever that the five-rayed ancestor, 

 which the holothurians must have had in common with the other 

 classes, was less developed than many cystids. Prof. Boole's ' hypo- 

 thetical Pentazoon ' is not the most ancestral form that is shadowed 

 forth to us, either by embryology or by palaeontology. 



Special praise is due to the illustrations, which have nearly all 

 been drawn for the work, under Prof. Eoule's direction, by Mr L. 

 Jammes, in a style that is at once original and effective. We must, 

 however, protest against the picture on p. 1275, purporting to repre- 

 sent living crinoids, " dans un fond rocheux de convention " (penny 

 peep-show convention). Attached to one of these marvellous rocks, 

 by a stem far too short in proportion to its arms, is a Pentacrinus ; 

 how it is fixed one cannot tell, but certainly not by the cirri, as 



