788 NATURAL SCIENCE. y^<-.. 



The chapters on animal classification are the weakest. Metazoa 

 are divided into Vertebrata and Invertebrata. Of the latter, it is 

 stated that the nerve cord or cords are never dorsal. Dr. Campbell 

 must know \e.xy well that there are dorsal cords in both nematodes 

 and Ba/anogiossus. The further subdivisions and reasons given for 

 them are not at all good. Sponges do certainly )iot " form the con- 

 necting link between the unicellular animals on the one hand and 

 multicellular animals on the other." The classification of Vermes is 

 quite inadequate. 



Of course classification of the Animal Kingdom in a few pages 

 is impossible, and its details to anyone who intends to get no further 

 than elementary work are useless. But Dr. Campbell should have 

 taken more care with this part or omitted it altogether. 



Otherwise, the book is well treated, and seems quite suitable for 

 its purpose. P. C. M. 



An Introduction to the Study of Botany, with a special chapter on some 

 Australian Natural Orders. By Arthur Dendy, D.Sc, and A. H. S. Lucas, 

 M.A. Pp. XV. and 271. Illustrated. Melbourne: Melville, Mullen and Slade, 

 1892. 



There is certainly no dearth of text-books on Botany, yet each new 

 teacher of the Science is fain to admit, like the authors in the present 

 case, that " hitherto no single elementary book has been sufficient to 

 fulfil all requirements," and forthwith to compile a new one which 

 may be above or below the average. The requirements are, perhaps, 

 sufficient justification for the appearance of the work before us, in 

 which Messrs. Dendy and Lucas combine an account of the general 

 structure and life-history of plants, with a special study of Australian 

 forms. 



The book is divided into two parts. Part I. (General Botany) 

 is a progressive study of the series of plant-forms, commonly known 

 as types, which are nowadays considered to illustrate best the various 

 groups and the advance in complexity of structure and function from 

 the lowest or simplest to the highest. The stonewort, Chara, has 

 been omittted, we think wisely, for it is certainly "a very aberrant 

 form," and therefore not one for an elementary text-book, though not 

 necessarily " of little value in comparative morphology." With the 

 description of structure is blended an explanation of function, and 

 except for occasional looseness the physiology is well and carefully 

 expressed. A few points, however, call for remark. The cells of a 

 plant should not be compared with the bricks of a house without 

 explaining the vital difference between the two, especially when in 

 the same page we read that they are generally " united together in 

 groups " to form tissue, which recalls the building of a house by the 

 bringing together of originally separate elements. 



In Chapter II., under Pvotococcus, starch, cellulose, and sugar are 

 mentioned as allied substances having a similar composition and 

 generally known as carbohydrates ; but the few words necessary to 

 explain wherein lies the similarity are wanting. Protococcus is also 

 described as a " typical " vegetable cell ; one hardly knows what to 

 understand by " typical," but a cell consisting very largely of proto- 

 plasm is certainly not the commonest form, which must rather be 

 sought in such an one as Vines adopts in his " Physiology " to 

 illustrate cell principles, namely, the ordinary tissue-cell with a delicate 

 " primordial utricle " lining the wall. In spite of a few blemishes like 



