NATURAL HISTORY OF THE EIGHTEENTH CENT. 393 



directly formed from lifeless elements by a kind of spontaneous gene- 

 ration ; that these rudimentary sketches -of animals and vegetables, 

 placed in suitable surroundings, develop little by little various organs 

 under the influence of the special circumstances by which they are 

 environed ; that the modification thus acquired tends to be preserved 

 by the property inherent in all living things of producing beings similar 

 to themselves ; that the change which every part of the surface of the 

 earth has successively undergone has given rise to varied conditions, 

 which have so modified the organs of living things, that they have 

 been by insensible degrees brought to that variety of form and develop- 

 ment in which we now behold them ; that species even now have only a 

 relative stability, and are not as old as the establishment of the present 

 order of things on the surface of the earth. Lamarck anticipates an 

 objection which nevertheless has since actually been again and again 

 urged against the transformation of species. The animals which have 

 been embalmed in the Pyramids of Egypt for several thousand years. 

 can be recognized as identical in every respect with those which still 

 exist there. Now, says Lamarck, it would be very singular if they 

 were otherwise, for the position and climate of Egypt are to-day very 

 much the same as they were three thousand years ago. The stability 

 of things in nature, he truly says, is but an illusion, for man judges 

 only by the changes he witnesses : compared with the changes which 

 he observes the earth has undergone when he. considers its condition 

 at periods relatively to him immensely remote, an intermediate age 

 may appear, by reason of the shortness of his existence, a stable con- 

 dition indefinitely prolonged. Lamarck then cites the known changes 

 in organization which changes of habit have produced, as in the case 

 of domestic fowls, etc., and refers to the extinct animals and plants as- 

 proving at once the continuity of nature and the existence of diverse 

 environments in past geological epochs. 



Naturalists would waste their time in vain by describing new species 

 and noting minute shades of difference if their labours had no other 

 result than to add to the long list of registered species ; and equally 

 vain would be the labour of arranging and rearranging species into 

 genera by one set of considerations after another, unless these re- 

 arrangements tend to present the animal series in relations more and 

 more conformable to those in which the animals stand by the operation 

 of nature. Our classifications, artificial though the lines of demarcation, 

 will be perfect only when they present the succession and connection 

 of species in the order and relation in which nature has placed them. 

 These relations are discoverable only by comparison of the organiza- 

 tion of the individuals, and the degree of importance of the different 

 kinds of organs must be considered. Lamarck lays great stress on 

 the progressive " degradation " or simplification which is observed in 

 the organization of .animals as we descend in the scale from the more 

 to the less highly organized classes. The indication of this progressive 



