LINNEA'N SOCIETY OP LONDON. 29 



neous generation in tlie most simple forms of life only. He says 

 it is not proved not to be the case. 



A most extraordinary passage deals with the kind of matter 

 whicli should most readily receive the first traces of organization. 

 It should be of gelatinous or mueo-gelatiuous consistence, cohe- 

 rent, but verging on fluidity. Here is Lamarck's physical basis 

 of life. 



There is a short paper in the ' Philosophic Zoologique,' "Des 

 Especes dites perdus." He notices that very few fossils are 

 exactly like existing species, that it is not safe to argue that the 

 floor of the sea and the remote parts of the eartli may not yield 

 species hitherto considered to be extinct. He states that when 

 any fossils belong to recent species, they are found in the newest 

 strata; and he asks. May not extinct species be really existing in 

 the form of recent ones into which they have joassed by modification 

 during long periods of time ? 



Then he takes up the argument that altered conditions, climate, 

 and the necessary wandering over the earth necessitate changes 

 in tlie hesoins {loants and habits) of animals. That if organs are 

 not used as much as formerly they degenerate, and, on the 

 contrary, they increase and alter with extraordinary use. So 

 that in long periods the hesoin leads to specific modifications. 



It is perfectly evident to every student of Lamarck who reads 

 for information and not to jest, that the lesoin (ivant, require- 

 ment) is not a positive active wish on the part of the animal. 



With regard to the Vegetable Kingdom, Lamarck accounts for 

 variation by alterations in tlie nutritive and circulatory processes. 

 He stated that the Animal Kingdom arose with the lowest forms, 

 iuid that the wonderful complexity of the highest is due to 

 ])rogressive modifications due to changes in external conditions 

 during long periods. The earth itself has been subject to a law 

 of general progress ; and it is not necessary to suppose universal 

 catastrophes. 



As if to complete the argument, Lamarck treats of the influ- 

 ence of cultivation on plants, and writes, as regards animals : — 

 " How many very diflerent races amongst our pigeons and fov\ Is 

 are produced by raising them under different conditions in dif- 

 ferent countries. We may look for them in vain in JN^ature." 



Lamarck divided the Animal Kingdom into animals which are 

 apathetic — those which move in consequence of the excitement 

 of structural irritability. Others have sensations added. Others 

 have irritability, sensation, consciousness, and the faculty ot 

 evolving certain ideas, and of using a will subject, however, to 

 propensities definite in their object. Others form correct ideas, 

 think, and have a free will and no overruling propensities. He 

 distinctly relates these faculties to organs which have become 

 evolved during ages with the other moditicatiuns of specific forms. 

 Sensation, will, proclivity, capacity for evolving ideas and utili- 

 zing them are successive steps accompanying progressive com- 

 plexity of organization. 



