FUNDAMENTAL RELATIONS OF ANIMALS 65 



rialists, for the establishment of the laws regulating the inorganic 

 world, it is yet denied by so many physicists with reference to the 

 introduction of organized beings at different successive periods. Does 

 this not rather go to show the imperfect acquaintance of these in- 

 vestigators with the conditions under which life is manifested and 

 with the essential difference there is between the phenomena of the 

 organic and those of the physical world, than to furnish any evidence 

 that the organic world is the product of physical causes? 



SECTION XVI 



RELATIONS BETWEEN ANIMALS AND PLANTS 

 AND THE SURROUNDING WORLD^^ 



Every animal and plant stands in certain definite relations to the 

 surrounding world, some, however, like the domestic animals and 

 cultivated plants, being capable of adapting themselves to various 

 conditions more readily than others; but even this pliability is a 

 characteristic feature. These relations are highly important in a 

 systematic point of view and deserve the most careful attention on 

 the part of naturalists. Yet the direction zoological studies have taken 

 since comparative anatomy and embryology began to absorb almost 

 entirely the attention of naturalists has been very unfavorable to the 

 investigation of the habits of animals, in which their relations to one 

 another and to the conditions under which they live are more espe- 

 cially exhibited. We have to go back to the authors of the preceding 

 century^- for the most interesting accounts of the habits of animals, 

 as among modern writers there are few who have devoted their chief 

 attention to this subject.^^ So little, indeed, is its importance now ap- 

 preciated, that the students of this branch of natural history are hardly 



*^ [This section is an example of Agassiz's superior ability to identify basic questions 

 and to make incisive observations in zoology. It is still pertinent from a modern view- 

 point.] 



*^ Rene Antoine de Reaumur, Memoires pour servir a Vhistoire des Insectes (6 vols., 

 Paris, 1734-1742); Buffon, Histoire naturelle generale et particuliere (44 vols., Paris, 

 1749-1804). 



^John J. Audubon, Ornithological Biography, or an Account of the Habits of the 

 Birds of the United States of America (5 vols., Edinburgh and Philadelphia, I83I- 

 1839); Thaddeus W. Harris, Report on the Insects of Massachusetts Injurious to Vege- 

 tation (Cambridge, Mass., 1841; 2d ed., Boston, 1852). 



