94 RAMBLES OF A NATURALIST. 



of the three kingdoms of nature.* This doctrine, 

 which was generally adopted, was simple, and ap- 



* Bonnet, who was one of the principal supporters in Natural 

 History of this doctrine of continuity, which Leibnitz employed to a 

 certain extent as the basis of his philosophy, was born at Geneva, in 

 1 720, and died in the same town in 1793. This natural philosopher 

 devoted himself with much ardour to microscopical studies, and his 

 researches on the reproduction of the Aphides, on Fission, and on 

 Vegetation proved that he possessed, to a high degree, a talent for 

 observation. In consequence of partial loss of sight, he abstained 

 from scientific pursuits, and devoted himself to those philosophical 

 and religious meditations which the contemplation of nature 

 inspires. Cuvier justly and forcibly denounced the false and dan- 

 gerous views which Bonnet had endeavoured to introduce into 

 science by this doctrine of continuity, and although this hypothesis 

 is generally abandoned at the present day it was also maintained by 

 Ducrotay de Blainville, who was born at Arques, in 1778, and who 

 died in Paris in 1850, after having attained to the dignity of a seat 

 in the Institute, and to a Professor's chair at the Jardin des Plantes 

 and the Faculty of Sciences at Paris. In his youth he was exposed to 

 many vicissitudes, for while a student at the Military School at 

 Beaumont, he escaped from the establishment and concealed himself 

 on board a vessel of war, from whence he came to Paris, and was 

 successively a pupil at the Conservatoire of Music, and a student in 

 a painter's atelier. Up to the age of twenty-seven he had not 

 directed his attention to science, when a lecture, which he acciden- 

 tally heard from Cuvier, decided his vocation. Two years after- 

 wards he took the degree of Doctor of Medicine, and had become 

 the intimate friend of Cuvier ; but his irritable and captious temper 

 did not allow him to maintain these friendly relations. He was no 

 sooner nominated Professor by concours to the Faculty of Sciences 

 than he began to wage war against the labours of the man who had 

 been the first to give him a helping hand. This opposition, which 

 often warped his judgment and made him unjust, continued to the 

 end of his life. Blainville's reputation was due in a great measure 

 to this determined opposition to Cuvier, although he undoubtedly 

 possessed a keen and vigorous intellect. He lectured exceedingly 

 well, and he has left several important works, amongst others the 



