1860.] Proceedinr/s of the Aaiatic Society. 429 



those who might wish to enter in detail into the question, and satisfy 

 themselves of the soundness or unsoundness of Dr. Bronn's views, 

 to the original work, which had been published in Germán, French 

 and English, the latter translation by the Ray Society of London. 



The two fundamental laws laid down by Dr. Bronn as having re- 

 gulated the sequence of organisms from the earliest period to the 

 present time were : 



1. That there had been the operation of an independent produ- 

 cing power or forcé (Kraft) progressive in intensity and in its sphere 

 of operation. 



2. That the results of this power or forcé had been limited by, 

 and dependant upon, the nature and changes of the extern al condi- 

 tions of existence, such as climate, habitat, food, &c. 



With respect to the first law, a clear idea of the meaning of 

 progression could only be gathered from a consideration of the whole 

 range of organized beings, and the evolution of general propositions 

 concerning form, organization, and habits of life. In this way, it 

 was shewn that the criteria of higher types as compared with lower 

 were : — 



Iiiglier. Lower. 



Bilateral symmetry of form. Quadrilateral or circular sym- 



metry of form. 



Few homologous parts. Numerous homologous parts. 



Organs various, specialized to Organs few, fitted to perform 



discharge one or few functions, various functions, dispersed, and 



concentrated, and enclosed. superficial. 



Habits terrestrial. Habits aquatic. 



Breathing air. Breathing water. 



Food, (in the case of animáis) Food, (in the case of animáis) 



vegetable. animal. 



With respect to the second law, the conditions of existence might 

 be considered under two heads, viz. as : — ino?yanic, which bore 

 reference to terrestrial phenomena, such as temperature, climatal 

 zones, the compoaition of the atmosphere, and the distribution of 

 land and sea ; and organic, which included the supply of food, a con- 

 sideration which had been developed to an extent unanticipated by 



3 k 2 



