88 The Ottawa Naturalist. [August 



Erasmus Darwin (1731-1802), grandfather of Chas. Darwin, 

 was one of the poets of the evolution idea. Like some of the 

 early Greek writers he believed in the doctrine of spontaneous 

 generation, but in the lower forms of life only. In the chapter on 

 Generation in his "Zoonomia" (1794) he takes little account of 

 the laws of heredity, but believes that b}' the addition of parts 

 resulting from changes of environment exciting the "living 

 filament" into action, new characters are acquired and these are 

 capable of being transmitted. This theory it will be seen an- 

 ticipated that of Lamarck. 



THE LAMARCKIAN THEORY. 



Lamarck -(1744-1829) was the real founder of the modern 

 theory of descent and is the most noted scientist and writer 

 between the time of Aristotle and that of Chas. Darwin. Labor- 

 ing under discouraging conditions and receiving nothing but 

 disdain by the majority of his contemporaries he succeeded 

 nevertheless in contributing much to natural science. In his 

 "Philosophic Zoologique" ' (1809) he expresses certain views 

 which correspond closely with those held by E. Darwin and 

 expressed by him in his Zoonomia. The main theory which 

 Lamarck advanced and which is now known as the Lamarckian 

 theory in contradistinction to the Darwinian theory, claims that 

 evolution takes place through the inheritance of characters 

 acquired during the lives of individuals so that in time new 

 species may be created. The endeavour to satisfy certain wants 

 brings about certain modifications which are inherited in part at 

 least. This theory made no great impression at the time although 

 it has been revived within recent times by a school known as the 

 Neo-Lamarckians to which school Herbert Spencer and other 

 prominent scientists belong. While the theory seems to explain 

 many of the facts of inheritance yet it fails to show a case wherein 

 a single acquired character has been permanently transmitted. 

 As an instance we have the continued docking of horses and lambs, 

 yet there is no case on record of one of these animals being born 

 without a tail. 



Goethe (1749-1832), the great poet of evolution, developed 

 the "unity of type" idea in 1796. This led him to explain the 

 existence of vestigial structures which constitutes one of the 

 strongest evidences of evolution. 



Bory de St. Vincent (1780-1846) beheved that species are 

 formed spontaneously and that this process goes on more rapidly 

 in countries of comparatively modern formation. His idea was 

 that the existence of a long series of ancestors tends to fix the 

 type. 



