CH. xxxvin. METAMORPHOSIS OF PLANTS. 413 



many more have been added since, yet a large number of 

 those which he worked out have been permanently adopted 

 The Natural System obliges botanists to take into account 

 every part of a plant before placing it into a family or order, 

 and as it is often very difficult to determine which are the 

 chamcters of most importance, there is a good deal of 

 difference between the arrangements adopted by one botanist 

 or by another. But though this is tiresome to pupils, it has 

 been very useful in science, for it has served to bring out 

 most clearly the way in which plants are related to each other, 

 and the fact that in Nature there are not sharp distinctions 

 between different kinds of plants, but that a particular species 

 may be very closely allied in some of its characters to one 

 family and In others to another, so that it is perhaps hardly 

 too much to say that our great advance in botany in the 

 present century has arisen from two things (i) from the 

 attempt to classify plants according to their natural affinities ; 

 and (2) from discoveries made with the microscope, begun, 

 as we saw, p. 136, by Grew and Malpighi in the seventeenth 

 century, and carried to perfection in our day. 



The great Swiss botanist Auguste Pyrame de Candolle 

 (1778-1841) did a great deal to spread the Natural 

 System by adopting it in his works, and also by modifying 

 it in many ways ; and still further improvements have been 

 made by the great Scotch botanist Robert Brown (1773- 

 1858), and by Endlicher (1804-1849), and Lindley (1799- 

 1865). 



Goethe's Theory of the Metamorphosis or Trans- 

 formation of Plants, 1790 We have said that the study 

 of the Natural System led botanists to observe more care- 

 fully the nature of plants and the manner in which they 

 grow. One of the first men who threw any light upon the 

 history of the growth of plants was the poet Goethe. Goethe 



