NATURAL HISTORY OF THE EIGHTEENTH CENT. 389 



which Lamarck published at various periods, need not here be noticed, 

 as we are now concerned chiefly with his contributions to zoological 

 science. It may, however, be remarked that Lamarck was one of the 

 first to discard the notion of violent convulsions as the agents of the 

 vast changes which geology recognizes as having occurred on the sur- 

 face of our planet. He conceived that such agents as are now slowly 

 producing changes would be competent to produce all the transforma- 

 tions the earth's surface has undergone, in a space of time sufficiently 

 extended ; and as, in nature, time presents no difficulties and has no 

 limitations, so may thus the greatest effects have been produced by the 

 prolonged operation of comparatively small causes. Palaeontology also 

 is indebted to Lamarck for the important distinction of littoral from 

 deep-sea fossils. In 1802 Lamarck published a work on the Organiza- 

 tion of Living Bodies, and in 1809 appeared "Zoological Philosophy," 

 in which the ideas enunciated in the former work were more fully de- 

 veloped. His " Natural History of the Invertebrate Animals," pub- 

 lished in seven volumes, from 1816 to 1822, is his largest work, and it 

 was received by scientific men with universal approbation. This work 

 is concerned only with the description and arrangement of the vast 

 number of species embraced in the section of the animal kingdom to 

 which it relates. It remains a monument of the scientific labour of its 

 author, but of the amount of labour which such an undertaking in- 

 volves those only who have themselves wrought in the same field can 

 have any adequate conception. The greater part of the Invertebrate 

 division of the animal kingdom was then almost unexplored, in a 

 scientific sense. The classifying genius of Linnaeus, after dealing suc- 

 cessfully with the Vertebrata, left the other division in a state of chaos; 

 for, separating only Insecta, he left the class of Vermcs (worms), a kind 

 of limbo to which were consigned creatures of most dissimilar and in- 

 congruous descriptions. It was by exploring this confused and com- 

 paratively unknown region that Lamarck has earned the eternal grati- 

 tude of the systematic zoologist. The achievements of this illustrious 

 Frenchman will appear the more extraordinary, when we observe that 

 he did not commence the study of zoology until he was fifty years of 

 age. The scientific reputation which Lamarck and Geoffroy Saint- 

 Hilaire-ultimately attained justified, in the most remarkable manner, the 

 choice of these two men for the professorships of natural science at the 

 Museum. Strangely enough, each of them only began the study of his 

 special subject when he entered upon his professorship, and the one 

 was a mere youth, the other a man already middle-aged. Saint-Hilaire 

 at twenty-one years of age was studying mineralogy, under Haiiy, when 

 Daubenton said to him, " I take all the responsibility of your inex- 

 perience upon myself; have but the courage to undertake to teach 

 zoology, and one day it may be said that you have created a French 

 science." Fortunately for zoology, and especially for philosophical zoo- 

 logy, Saint-Hilaire had the courage. The investigation by Lamarck of 



