C38 

 Bio/, 

 PREFACE. L '^< 



THIS book may be described as an elementary practical 

 handbook of Vegetable Histology and Physiology, contain- 

 ing in addition a short course of practical work on selected 

 types of Cryptogams and Grymnosperms. It is divisible 

 into three sections, namely, (1) Histology Chapters I. to 

 III., (2) Physiology Chapters IV. to VII., and (3) Life 

 Histories Chapters VIII. to XII. 



In the first section (Histology), I have exercised special 

 care in giving clear and practical directions for microscopic 

 work. Chapter I. is devoted to this purpose and to 

 general instructions regarding the fixation and preservation 

 of material, the cutting of sections, the application of re- 

 agents, and other practical matters. 



In Chapter II. I have worked out a plan which has 

 proved thoroughly satisfactory in practice. In my opin- 

 ion, no candidate should be allowed to pass in Botany at 

 such examinations as the Intermediate Science and Arts 

 of London University unless able to produce satisfactory 

 proof of having worked through a practical course in 

 Organic Chemistry. Until examining bodies insist upon 

 this, the tea,cher of Botany must include in his course a 

 few lessons on the Biochemistry of plants. The student 

 ought to know something more about proteins, for in- 

 stance, than that they contain nitrogen and are coloured 

 brown by iodine solution ! 



The best makeshift plan I have been able to devise is 

 that of working through a series of test-tube reactions for 

 each of the important classes of vegetable organic bodies, 

 in each case proceeding to apply the knowledge thus gained 



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