THE STUDY OF PLANTS IN ANCIENT AND MODERN TIMES. 7 



vegetation of the remotest corners of the earth was ransacked by travelling 

 botanists without any material advantage being gained, though they not infre- 

 quently ran considerable risk to their health, and sometimes sacrificed their lives. 

 As one generation succeeded another thousands of students of the " scientia ama- 

 bilis" made their appearance in every country. Swept along by the prevailing 

 current of thought they devoted themselves to the examination of native and foreign 

 floras, or to a detailed study of the most insignificant sections of the vegetable 

 kingdom. Those who are not under the spell of this passion cannot conceive the 

 joy experienced by the discoverer of a hitherto unknown moss. To such it is 

 inexplicable how anyone can devote the labour of half a lifetime to a classification 

 of Algge or Lichens, or to a monograph of the bramble-tribe or orchids. The pro- 

 gress achieved eventually in this department of botany is best appreciated when 

 the wide difference in the numbers of species described in botanical works of 

 different periods is considered. Theophrastus in his Natural History of Plants 

 (about 300 B.C.) mentions about 500 species, and Pliny (78 a.d.) rather more than 

 1000; whereas, by the time of Linnaeus, about 10,000 were known; and now the 

 number must be all but 200,000. It should be remarked, however, that half the 

 plants described since Linnaeus lived fall into the category of Cryptogams, or non- 

 flowering plants, the examination of which was first rendered possible by the wide- 

 spread use of the microscope in recent times. 



The microscope led also to discoveries concerning the internal architecture 

 of plants. A faint attempt in this direction, made 200 years ago, had died away 

 without leaving any trace behind; but at the commencement of this century the 

 "inward construction of plants" was studied all the more eagerly by means of the 

 microscope. In buildings belonging to different styles of architecture it is not 

 only the forms of the wings, stories, rooms, and gables that differ, but also and 

 in no less degree those of the columns, pilasters, and decorations. The same is the 

 case with plants. They possess chambers at different levels, vaults, and passages. 

 They have pipes running through them, and beams and buttresses, some massive 

 and some slender, to support them. The pieces of which they are built vary in 

 size, and their walls are sculptured in all kinds of ways. It was the business of the 

 vegetable anatomist to dissect plants, to look into all these structures under the 

 microscope, to describe the various component parts as well as the ground-plan and 

 elevation of the plant-edifice as a whole; and to name the different forms of struc- 

 ture after the manner of Linnaeus when he invented terms for the different forms 

 of stems and leaves, and for the several parts of the flower and fruit. 



DOCTEINE OF METAMORPHOSIS AND SPECULATIONS OF 

 NATURE-PHILOSOPHY. 



Side by side with this immense volume of research, which was directed to the 

 separation, description, and synoptical arrangement of mature forms only, there 

 arose about the year 1600 another school which considered vegetable forms from 



