^14 Report S.A.A. Advancement of Science. 



the I'cnis and FUnccnng pluiils. This will exercise a meiUal t'acully 

 which has been called " Visualization." vi/.. the power to form a 

 solid transparent mental picture from the study of transverse and 

 longitudinal sections of an opaque solid, and generally to build up 

 complete ideas from isolated data. This branch of Botany is difficult, 

 and one which more perhaps than an\ other strains the interest of 

 the student. This is to some extent due to the fact that the organ 

 whose anatomy is under consideration is usually treated merely as 

 a dead object. Practical work in anatomy should however be enliven- 

 ed as far as possible by experimental demonstrations bearing upon 

 the functions of the organs studied. For example, the absorption of 

 liquids by roots, and their response to various stimuli, should be the 

 subjects of simple and easily intelligible experiments during the 

 period in which the root-structure is being learned. Light will also 

 be thrown upon leaf-structure by experiments on assimilation, and 

 by a consideration of some well-marked variations in structure which 

 are regarded as adaptations to different groups of external conditions. 

 The simple physiological experiments here referred to should give 

 the student a very definite idea of the relation of cause and effect, 

 and enal)le him to estimate the value of the evidence obtained by 

 jnitting a direct question to nature. In fact, they should be so carried 

 out as to give him a real if elementary notion of the principles of 

 research. The study of the general anatomy of the vegetative organs 

 will prepare the way for a more detailed examination of the structure 

 of the essential parts of the flower, which we were unable to deal 

 with at an earlier stage. The student should by this time have 

 acquired sufficient skill in manipulation to enable him to gain such 

 an idea of the structure of the anther and the ovule, and of the 

 development of pollen- and embryo-sacs as will enal)le him to under- 

 stand the principles of fertilisation and embryo-formation in the 

 (iymnosperms and Angiosperms. 



Before this course is entered u]»on the ideal student will 

 have followed a course of Nature stud\ and will have liecome 

 acquainted with some few plants, at least, of his native Flora. He 

 may even have so much knowledge of the subject as is required l)y 

 the syllabus of the I'niversit) Matriculation Fxamination. Occasion- 

 ally one meets with a student whose interest in the subject is such 

 that while following a lal)oratorv course he spends some of his .spare 

 time in collecting plants and ])ossibly in forming a private herbarium. 

 This .spirit should be encouraged as far as possible bv periodical 

 Botanical excursions conducted by the teacher. The principal objects 

 of these excursions will be to ol)serve the i)lants in their natural 

 hal)itats. the relations of one jilant to another and of one plant-societv 

 to another, their forms and habits as evidences of the influence of the 

 conditions under which they live. Tncidentallv the names of manv 

 ])lants will become familiar, though 1 do not regard this as a primary 

 ol)ject of the excursion. In any case the student should be en- 

 couraged and helped to identify his plants for himself rather than be 

 allowed to place his reliance upon the knowledge of another. With this 

 end in view, from the plants collected upon the excursions a small 



