4 i2 NINETEENTH CENTURY. PT. III. 



parison rare plants and animals formerly unknown, which 

 were eagerly studied for the new light they threw upon those 

 which had been already dissected and described. 



And so it came to pass that towards the end of the 

 eighteenth century, men became eager not merely to examine 

 separate specimens or structures, but to form theories about 

 the living beings on the globe. They began to inquire why 

 some animals should be so much alike in their general plan, 

 and yet so different in their special characters; why the 

 same part of the body should be made to serve for different 

 purposes in different animals, instead of a special organ being 

 provided ; as, for example, the wing of the bat, which answers 

 exactly to the front leg of a mouse, but is altered so as to 

 be used for flying instead of walking. Then again, as the 

 distribution of animals became better known, the question 

 arose why certain kinds, such as kangaroos, should be found 

 only in Australia, while they are wanting in all other parts 

 of the world. Such general questions as these began to 

 occupy the minds of naturalists, and we cannot close a 

 history of science without trying to understand something 

 of the attempts made to answer them. 



Natural System of Plants Bernard and Antoine de 

 Jussieu. Even while Linnieus was living, another botanist, 

 Bernard de Jussieu (1699-1767), had begun to carry out 

 his suggestion that plants should be classed by the agreement 

 of all their observable characters, and not merely artificially 

 by the number of their stamens. But Bernard did not pub- 

 lish his catalogue, and it was his nephew Antoine de Jussieu 

 (1748-1836) who first published a book in which the plants 

 were arranged according to the Natural System. It was 

 Antoine who first sketched out roughly the characters of 

 Families or Natural Orders ' as we have them now. He 

 made 100 families from the plants then known, and though 



