x: 



NATURE 



YJamiary i8, i8^ 



arrnngement of parts. The corallum is penetrated by an 

 intercommunicating series of canals which put the ccelen- 

 teraof all the polyps into communication with each other. 

 The mouth is elongated in the sagittal axis. The stomato- 

 doEuni is supported by twelve mesenteries. The two 

 pairs of directive mesenteries, and one mesentery on each 

 side (Nos. 4 and 9 of Fowler's Fig. 8) -which, as in the 

 Antipatharia, may be termed the transverse mesenteries, 

 and are the first to be developed — are more important 

 than the others, and extend to a lower level ; they are also 

 the longest,and are the only ones which bear reproductive 

 organs. Similar elongate mesenteries occur in Alyonaria, 

 in Antipatharia, and in Seriatopora and Pocillopora 

 amongst the Madreporaria. In Antipatharia, also, they 

 are the only ones which bear reproductive organs. The 

 present writer has more than once (Trans. Roy. Dublin 

 Soc. iv. 1889, p. 300 ; Proc. R. D. S. 1890, vii. p. 128) sug- 

 gested the employment of names for the primary mesen- 

 teries which are independent either of empirical numbers 

 or of the order of their appearance in ontogeny. Accord- 

 ing to that enumeration, here, as in the Actiniaria gene- 

 rally, the first mesenteries to appear are the sulculo-sulcar 

 laterals (Lacaze Duthiers' i, and Fowler's 4 and 9). In 

 JMadrepora Ditrvillei the other important mesenteries 

 ■are the sulculo-sulcular laterals and the sulcar directives, 

 to which must be added in M. aspera the sulcular di- 

 rectives. The inconspicuous mesenteries are the sulco- 

 sulcar laterals and the sulco-sulcular laterals (with the 

 addition of the sulcular directives in M. Diirvillei). 

 There may be details of structure peculiar to certain 

 species of Madrepora, or even to individuals, as in 

 dimorphic forms ; but the relative values of the several 

 mesenteries can be matched in the young and in some 

 adults of the Actiniaria, and in the larva of Euphyllia, 

 and among other Madreporaria. 



We cannot enter into the question of classification or 

 the characters upon which classifications have been 

 based; suffice it to say that Mr. Brook relies primarily on 

 the structure of the corallum. Very little is yet known 

 upon the arrangement of the soft tissues in their relation 

 to the corallum. It is to be expected that the varied skeletal 

 ■characters are the outcome of a difference in the struc- 

 ture or arrangement of the soft parts ; in the meantime 

 the corallum is all there is to deal with, and the author 

 has naturally assumed that a similarity of structure in- 

 volves a close relationship, and therefore places little 

 reliance on habit. To a certain extent the species fall 

 into well-marked groups, if one does not regard habit of 

 prime importance. The genus is divided into ten divi- 

 sions or sub-genera ; the chief place is given to the 

 character of the axial corallite (this is analogous to the 

 growing point of the stem or branches of a plant), and 

 secondly to that of the radial corallites which are pro- 

 duced by means of indirect budding around the wall of 

 an axial corallite. The texture of the corallum is also an 

 important diagnostic feature, and of least value is the 

 mode of growth or habit. We are at present quite in the 

 dark as to the reasons why individuals of the same 

 species should grow in a flabellate (or palmate) manner, 

 or be luxuriantly arborescent ; there ii, however, a 

 general tendency for the members of a morphological 

 group to have a similar habit of growth. 



Those who have attempted to name specimens of 

 NO. 1 264. VOL. 49] 



madrepores from the older descriptions will welcome this 

 masterly monograph; but it is to be regretted that outlme 

 figures illustrating the details employed in classitication 

 were not appended to the synopsis of the sub genera 

 on p. 22. The collotype plates, although beautifully 

 executed, illustrate more the general habit, and the 

 critical characters therein are not readily discerned. 



The genus Madrepora contains a large number of 

 species. Mr. Brook recognises 221, of which the British 

 Museum has 180 species out of a total of over 1100 

 specimens. Mr. Brook reduced 169 old species to 130 

 in number, but has been obliged to describe 91 new 

 species ; of these 62 appeared in the Annals of Natural 

 History for 1 89 1 and 1892. No fossil representatives 

 are alluded to. Mr. Brook had travelled extensively in 

 Europe in order to study the type specimens in various 

 museums, but he had not seen the types in American 

 museums. Eighty-six species are illustrated in the 

 twenty-five plates, which are beautiful collotypes by 

 Messrs. Morgan and Kidd, from the author's own nega- 

 tives. Owing to the necessity for large plates the mono- 

 graph is quarto in size, instead of the usual octavo of the 

 other catalogues of the British Museum. 



It is by no means an easy task to identify the species of 

 this genus, owing to their number and varied habit. The 

 genus Madrepora is now flourishing abundantly,and it is 

 difficult in some cases to determine whether certain forms 

 should be regarded as species or varieties. It is wide- 

 spread, abundant, and variable forms, such as these, which 

 are the despair of oid-fashioned systematists, but serve 

 as stimulating problems for the modern naturalist. 



Alfred C. Haddon. 



PH YSIOL O CICA L CUE MIS TR V. 

 Physiological Clieniistry of tJie Animal Body. By Arthur 

 Gamgee, M.U., F.R..S. Vol. II. The Physiological 

 Chemistry of Digestion. (London : Macmillan and 

 Co., 1893.) 



THE examination of the su'-ject of physiological 

 chemistry may obviously be made from two separate 

 points of view. In the first place, the different problems 

 of the subject may be discussed from the standpoint of the 

 organic chemist, who looks to physiology for illustration 

 and extension of truths established by laboratory practice. 

 In the second place, the various chemical processes 

 occurring in the animal body maybe considered from the 

 biological standpoint, and here the domain of chemistry 

 is invaded simply as far as necessity compels for the 

 adequate comprehension of the biological problems 

 presented. 



The result of writing a treatise from either of these 

 points of view alone is to largely limit the usefulness of 

 the work, and yet it requires no inconsiderable courage 

 to attempt to furnish a work which may be of important 

 service both to the chemist and biologist. Dr. Gamgee 

 has, however, been inspired with the courage of his well- 

 recognised ability, and has presented the scientific world 

 with a work which must at once appeal to the chemist 

 for the thoroughness of its chemical explanation and de- 

 tail, and to the biologist for the general completeness of 

 its critical review of physiological woik. 



