40 INTRODUCTION. 



views. Peculiarities of economy (and herein almost every spe- 

 cies of animal differs from its neighbour,) necessarily involve 

 corresponding peculiarities of organization, at times, indeed, 

 minute, and to be sought after with great care and labour, and 

 often with the assistance of the microscope. The philosophi- 

 cally minded student will therefore combine with the observa- 

 tion of habits, investigation of structure, and in this latter par- 

 ticular lies the merit of such laborious naturalists as Lyon- 

 net, Swammerdam, or Strauss-Durckheim, who lay open to 

 our view the minute intricacies of the internal anatomy of 

 various species of insects. The following observations upon 

 the connexion between these two branches of our subject, 

 from the " Introduction to the Menageries," will be read 

 with pleasure, from the soundness of the views which they 

 inculcate : " It is amazing how much quickness the habit of 

 observation will impart to the whole intellect, and give it an 

 aptitude for understanding and enjoying the thing observed. 

 There is nothing, for instance, so common as to find men 

 wanting in a perception of picturesque beauty, of that feel- 

 ing which enables some to take great delight in a landscape, 

 not only for its extent, or the grandeur of its parts, but for 

 the harmonious arrangement which is necessary to the effect 

 of a picture, or for some accidental circumstances of light 

 and shadow, or of colour, which render the prospect more 

 than usually attractive. Now this is strictly an acquired 

 faculty, and one which is produced by the practice of looking 

 at nature, or at the monuments of art, with the previous 

 adaptation of the vision to picturesque objects ; and a per- 

 son who enjoys the faculty (we say enjoy, for it is a source 

 of real pleasure) is said to possess a painter's eye. It is pre- 

 cisely in the same way that a naturalist, by constantly ob- 

 serving the peculiarities of animal life, acquires the readiest 

 perception of the differences in the structure and habits of 

 the great variety of living beings, and he perceives in each of 

 them qualities which a less practised observer would entirely 



