ON THE STUDY OF BIOLOGY. 537 



ers, mean. If he does not do that, he may read till the crack of doom, 

 hut he will never know much about chemistry. That is what every 

 chemist will tell you, and the physicist will do the same for his branch 

 of science. The great changes and improvements in physical and 

 chemical scientific education which have taken place of late have all 

 resulted from the combination of practical teaching with the reading 

 of books and with the hearing of lectures. The same thing is true in 

 biology. Nobody will ever know anything about biology, except in a 

 dilettant " paper-philosopher " way, who contents himself with read- 

 ing books on botany, zoology, and the like ; and the reason of this is 

 simple and easy to understand. It is, that all language is merely 

 symbolical of the things of which it treats ; the more complicated the 

 tilings, the more bare is the symbol, and the more its verbal definition 

 requires to be supplemented by the information derived directly from 

 the handling, and the seeing, and the touching of the thing symbol- 

 ized : that is really what is at the bottom of the whole matter. It 

 is plain common-sense, as all truth in the long-run is, only common 

 sense clarified. If you want a man to be a tea-merchant, you don't 

 tell him to read books about China or about tea, but you put him into 

 a tea-merchant's office, where he has the handling, the smelling, and 

 the tasting of tea. Without the sort of knowledge which can he 

 gained only in this practical way, his exploits as a tea-merchant will 

 soon come to a bankrupt termination. The u paper-philosophers " are 

 under the delusion that physical science can be mastered as literary 

 accomplishments are acquired, but unfortunately it is not so. You 

 may read any quantity of books, and you may be almost as ignorant 

 as you were at starting, if you don't have, at the back of your minds, 

 the change for words in definite images which can only he acquired 

 through the operation of your observing faculties on the phenomena 

 of Nature. 



It may be said : "That is all very well, but you told us just now 

 that there are probably something like a quarter of a million different 

 kinds of living and extinct animals and plants, and a human life could 

 not suffice for the examination of one-fiftieth part of all this." That 

 is true, but then comes the great convenience of the way things are 

 arranged ; which is, that, although there are these immense numbers 

 of different kinds of living things in existence, yet they are built up, 

 after all, upon marvelously few plans. 



, There are, I suppose, about 100,000 species of insects, if not more, 

 and yet anybody who knows one insect if a properly-chosen one 

 will be able to have a very fair conception of the structure of the 

 whole. I do not mean to say he will know that structure thoroughly, 

 or as well as it is desirable he should know it, but he will have enough 

 real knowledge to enable him to understand what he reads, to have 

 genuine images in his mind of those structures which become so vari- 

 ously modified in all the forms of insects he has not seen. In fact, 



