HERBARIA IN THEIR RELATION TO BOTANY. 361 



herbaria, a significance being given to the word which it has 

 now lost. It soon became painfully evident that very good and 

 conscientious descriptions, even when accompanied by accurate 

 plates, were yet not adequate to express all those delicate details 

 which the living plant showed. So some of the authors found a 

 way to keep the plants they had described, at first for their own 

 reference, and for this purpose dried them carefully, glued them 

 on sheets of paper, and put the name on this paper. Preserved 

 in this way and arranged alphabetically for easy reference, these 

 specimens formed a supplementary confirmation of their descrip- 

 tions which was readily accessible. This was what we now call a 

 herbarium in other words, a collection of well-preserved, care- 

 fully named dry plants. If the description of an author who had 

 a collection of this sort was called in question, it was an easy 

 thing for him to send his original plant to some third botanist, 

 who could decide whether he was right. Afterward it was rec- 

 ognized by those who described new plants that it would be of 

 great importance to them if they could have the originals of 

 the descriptions of their fellow-botanists. So a system of in- 

 terchange of originals arose, which is now carried on between 

 botanists all over the world. A trained and competent botanist 

 who finds an opportunity to study the flora of regions which 

 are little known may by this means become possessed of all 

 the most instructive and remarkable plants that are known to 

 science. 



So a modern botanist no longer collects, as was formerly 

 done, only one or two samples of every plant, but one or two 

 hundred of rare species often two thousand because every 

 specimen he has will enable him to obtain some new one in 

 exchange. 



The difficulties of collecting in the present time may be esti- 

 mated from this. To collect four thousand plants in a tropical 

 climate means not only to find, dry, and name these under the 

 most unfavorable conditions, but to prepare perhaps forty thou- 

 sand, all the duplicate specimens being used in exchange. 



For a long while plants were named by any word which took 

 the fancy of its author, and were arranged in the alphabetical 

 order of the names. Soon, however, it was found that a better 

 disposition was desirable, as nobody could look over such exten- 

 sive alphabetically arranged collections, and students began to 

 assort the plants in such a way that those which had certain 

 characteristics in common were grouped in classes. So, for exam- 

 ple, all kinds of grasses, all kinds of trees, all kinds of shrubs 

 were put together, etc. Such a beginning of classification and 

 unconscious recognition of relationship was begun by Lobelius 

 and Bauhin, extended by Csesalpin, and completed by Linnaeus. 



VOL. XLVII. 30 



