358 SCIENCE PROGRESS 



special modes of life, e.g. the aquatic, alpine, and xerophytic conditions. Further, 

 insistence is made upon the necessity for studying the constancy of characters 

 within a species — an unsettling admission neutralised to a large extent, however, by 

 the reflection that variations of this type would appear never to exceed certain 

 fixed limits. Bearing these qualifications in mind, there can be little doubt that 

 the anatomical method — still but a young branch of Botany — will accomplish much. 

 Much, indeed, has already been done ; and the important place ascribed to 

 anatomical considerations in Die naturlichen Pfianzenfamilien of Engler and Prantl 

 — a monumental work affording probably the most natural scheme of classification yet 

 produced — is sufficient evidence that the value of these criteria is realised by some 

 of the greatest systematists. There is, however, another aspect of the question, for 

 Solereder's work is a " Handbook for Laboratories of Pure and Applied Botany." 

 The anatomical method has for a long time been employed in pharmacognosy and 

 in work dealing with the detection of food adulterants, but in this country, at any 

 rate, comparatively little systematic work has been done on these lines ; and the 

 application of botanical histology to the identification of the innumerable other 

 economic products of the vegetable kingdom may be said to be practically non- 

 existent. But there is strong evidence that this state of things will not long be 

 permitted to remain. In this country, as well as abroad — notably in Germany and 

 the United States — increased attention is being given to the question of the 

 adulteration of foodstuffs and drugs. For the detection of the impurities, exact 

 methods of microscopical examination are necessary, and that the resources of 

 botanical science are fully capable of dealing with the problem is evidenced by the 

 fact that the recent revision of the legislation dealing with food and drug adultera- 

 tion in Germany has resulted in the appearance of exact scientific treatises — 

 notably the Pkarmakognostich.es Praktikum of Koch and Gilg — intended for the 

 training of those to be entrusted with the maintenance of the purity of these 

 articles ; and in the United States the increased attention given to similar matters 

 has been accompanied by the translation into English of Hanausek's LeJuintcJi der 

 technischen Mikroskopie,a.x\& the appearance of related works ofWinton and others. 

 The book forming the subject of the present notice has long been recognised as 

 one of the most valuable aids in this branch of work, and the appearance of an 

 English edition will be warmly welcomed by all economic botanists in this country as 

 an invaluable help in elucidating the difficult problems with which they have to deal. 

 In finally surveying the work of the anatomical school, there can be little doubt 

 that it should be cordially received by the systematists. The ultimate aim of 

 systematic botany is the formulation of a scheme of classification which shall 

 illustrate — so far as is humanly possible — the true natural relationships of plants, 

 fossil and recent. For the complete attainment of this end evidence of every 

 kind must be brought to bear — evidence of the fossil record, of morphology, 

 anatomy, physiology, and teratology. Moreover, the majority of botanists now 

 realise that the evidence of the sister sciences must not be neglected, notably that 

 of chemistry. Soleredcr himself strongly emphasises the assistance which could 

 be rendered by micro-chemistry, but deplores the imperfection of existing methods 

 and the great difficulties of technique which render this line of work com- 

 paratively sterile. From this point of view probably one of the most satisfactory 

 pieces of systematic work yet carried out is that of Baker and Smith in A Research 

 on the Ei/calypts, especially in regard to their Essential Oils (1902), in which the 

 authors — a botanist and a chemist working conjointly — were led to revise the 

 usually accepted classification of an important genus, and to formulate another 

 based upon habit, characters of timber and bark, and the chemical and physical 



