472 THE STORY OF PLANT LIFE 



plants, it is enough to be provided with a set of dissecting 

 instruments, camel-hair brush, watch glasses, pins, paper, 

 drawing materials or water-colour outfit for sketching, note- 

 book and pencil, and, above all, a good magnifying lens, or 

 simple dissecting microscope, for examination of the external 

 features and juxtaposition of parts of the flower — the smaller 

 details. This applies also to external features or surface 

 of roots, stem, leaves, fruits, etc., including stomata, hairs, 

 glands, lenticels, etc. Here the form and structure of organs 

 — not their function and action, or mode or rate of growth, 

 or other activities — are concerned. Hence work lies rather 

 in the accurate observation of form and outline, relation to 

 other parts, and comparison between homologous parts in 

 other plants. 



This part of the work may be confined to the examination 

 of selected types, as adopted in text-book syllabi ; or it may 

 be extended to the study of all available types, and the 

 intimate acquaintance between allied orders, genera, or 

 species. Such a course will assist the student in working 

 out the phylogeny of species, and form the basis of a more 

 natural system of classification than can be arrived at by 

 a mere study of specific characters. For these purposes 

 herbarium material, or fresh material, will be useful ; but it 

 must be supplemented by material preserved in alcohol, 

 formol, or other media such as phenol, glycerine, etc. (see 

 Lee's 'Microtomist's Vade-mecum,'' Zimmerman's 'Botanical 

 Microtechnique,' Stevens' 'Plant Anatomy,' etc., Tagg in 

 * Trans. Bot. Soc. Edinburgh'). 



In the case of sections of root, stem, leaves, or other parts 

 involving a study of the internal anatomy, cytology (see 

 Walker, ' Essentials of Cytology '), histology, embryology of 

 plants, other methods are required ; for the examination 

 of cells, tissues, their contents, structure, form, arrangement, 

 and the study of a sequence of internal changes — e.g. 



