196 The Evolution of Botany. 



ABSTRACT OF THE DISCUSSION. 



Da. ROBERT G. ECCLES : 



In the absence of Prof. Ridenour, who had been appointed to open 

 the discussion, DP. Eccles was called upon by the president, and, said, 

 in substance : I desire to thank the lecturer for the condensed and 

 admirable account of the evolution of botanical science which he has 

 given us. I do not know that such a succinct and correct statement 

 of the history of botany can be found elsewhere in the literature of 

 that subject. In one sense botany antedates historical knowledge, 

 and butterflies show an earlier knowledge of plants than man can 

 boast. As a science, however, botany is of more recent growth. In 

 the investigation of such subjects, one thing that strikes the student 

 of nature is that everything in nature follows a single law of growth, 

 progressing from homogeneity to heterogeneity, the same law that we 

 see exemplified in its simplest form in the growth of a tree or shrub. 

 Everything spreads, as it were, from a single trunk into branches, 

 limbs, and twigs. We find the same principle illustrated in the form 

 of the human body and in the structure of the brain in the branch- 

 ing of the nerves from their central spinal axis which is everywhere 

 found in the plant world. The same phenomenon has even been ob- 

 served in the lightning flash. When photographed, instead of pre- 

 senting the appearance of a single line of light, it appears as if differ- 

 entiated into tree-like branches. This principle of differentiation is 

 also exemplified in the evolution of the science of botany. At first, as 

 we have been told, our knowledge of plant-life was vague, homogene- 

 ous, and protoplasmic, consisting only in^ the recognition of certain 

 familiar descriptive characteristics of well-known plants. As the 

 science developed, its several departments were integrated and special- 

 ized. Now no single botanist can be a master of all branches of the 

 science. He can acquire eminence only by perfecting himself in some 

 one special department of research. The study of botany thus leads 

 steadily up to evolution. Unless God designed to deceive the whole 

 world, it is clear that the doctrine of evolution must be true. 



In enumerating the botanical text-books published in this country, 

 I think mention should be made of the valuable manual prepared by 

 Miss Eliza A. Youmans, now a corresponding member of this associ- 

 ation. 



