ANNOTATIONS AND ADDITIONS. 301 



sensible difference between America, India, and the "West Coast of 

 Africa. The distribution of organic beings over the surface of the 

 earth does not depend wholly on thermic or climatic relations, which 

 are of themselves very complicated, but also on geological causes 

 almost unknown to us, belonging to the original state of the earth, 

 and to catastrophes which have not affected all parts of our planet 

 simultaneously. The large pachydermatous animals are at the pre- 

 sent time wanting in the New Continent, while we still find them 

 in analogous climates in Asia and Africa. These differences ought 

 not to deter us from endeavoring to search out the concealed laws 

 of nature, but should rather stimulate us to the study of them 

 through all their intricacies. 



The numerical laws of the families of plants, the often striking 

 agreement of the numbers expressing their ratios, where yet the 

 species of which the families consist are for the most part different, 

 conduct us into the mysterious obscurity which envelops all that is 

 connected with the fixing of organic types in the species of plants 

 and animals, or with their original formation or creation. I will 

 take as examples two adjoining countries which have both been 

 thoroughly explored France and Germany. - In France, many 

 species of Grasses, Umbelliferse and Cruciferae, Compositse, Legumi- 

 nosae, and Labiatse are wanting, which are common in Germany; 

 and yet the numerical ratios of these six great families are almost 

 identical in the two countries, as will be seen by the subjoined com- 

 parison. 



Families. Germany. France. 



Gramineae. T ' 5 T ^ 



Umbelliferae^ ^ 2> T 



Cruciferse. T ' - T ^ 



Compositse. . 4 



Leguminosae. -fa y ff 



Labiataa. ^ fa 



This agreement in the number of species in each family compared 

 to the whole number of phaenogamous species in the Floras of France 

 and Germany, would not by any means exist if the German species 

 which are missing in France were not replaced there by other types 

 belonging to the same families. Those who are fond of imagining 

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