XlV. INTRODUCTION. 



judicious local influence brought to bear upon it, may prove 

 both useful and creditable ; but why should not wealthy 

 communities, possessing endless drawing-rooms ablaze with 

 costly decorations, exercise something of a corresponding 

 liberality towards the museum of natural history, which is 

 the representative of their appreciation of that which is 

 higher than the highest art? 



Considerable difficulty has been found in selecting appro- 

 priate materials for the printed tablets. Many of the chief 

 continental authorities on invertebrate animals, admirable as 

 are their works for the purpose of identifying species, afford 

 scarcely a line of information on the life history of the 

 objects they so grandly figure, and often so elaborately 

 describe. Even the reports of scientific expeditions may fre- 

 quently be searched in vain for this kind of information, 

 which has to be gleaned from authorities not always trust- 

 worthy, from scattered papers, or from a few books of travel 

 such as those which have been issued in this country on the 

 Malay Archipelago and the River Amazon, and more recently 

 on Nicaragua. 



It is mortifying to have to exhibit forms distinguished by 

 extraordinary developments of structure, and to be able to say 

 nothing on associated habits. Such strange developments 

 were once considered to be mere freaks of nature, but no one 

 now doubts their having a biological and even a genealogical 

 significance. What a field is here opened ! How little of 

 the biology of a new form has been exhausted when it has 

 been collected, named, described, figured, and even dissected. 

 Scientific treatises have prepared the foundation for a solid 

 knowledge of the subject; but there would be occasion for 

 regret if biology should ever come to be regarded by students 

 in an aspect too exclusively morphological, histological, or 

 even physiological, if such a view operated to the disparage- 

 ment of genuine out-of-door observations. The greatest 



