S06 PRACTICAL AND SCIENTIFIC ZOOLOGY. 



raulgated^ will never compensate for the want of this 

 primary requisite. In ordinary life^ we see some people 

 who have an instinctive perception of differences to a 

 much greater degree than others : as if^ in short, the 

 faculty was natural to them. Such persons will always 

 make the best naturalists. This keenness of perception 

 can, doubtless, be acquired ; and, as no science requires 

 more observation, or greater nicety of discrimination, 

 than natural history, so, upon this account only, it is 

 the very best pursuit that can engage the youthful 

 mind ; since it will be thus qualified to apply that 

 acuteness and judgment upon greater things, in after- 

 life, which may call for the exercise of sound reason and 

 just discrimination. ]\Iany people, for instance, would 

 be utterly at a loss to discover the difference of structure 

 between a swift and a swallow, even if the two birds 

 were before their eyes. Their colours, it is true, are 

 not the same ; but both have little, triangular, short 

 bills, long pointed wings, and fly and feed in the same 

 manner. A glance, however, at their feet shows a ma- 

 terial difference. This difference is so great, that a 

 young naturalist would immediately be convinced they 

 could not belong to the same genus ; because these op- 

 posite structures of the feet indicated a corresponding 

 dissimilarity of manners. Again, we hear the names 

 of butterfly or moth used indiscriminately, even by well- 

 informed people ; who, were they asked why, could 

 give no satisfactory answer. A boy, who merely knew 

 the first elements of entomology, might immediately 

 answer by pointing to the antenna;, or horns (as they 

 are vulgarly called), of the insect, and stating, that in a 

 butterfly these members end in a thickened knob; 

 ■while in the generality of moths they terminate in a fine 

 point. This tact for observation, like every other habit, 

 is to be acquired by practice ; and the more it is exer- 

 cised, the more acute it becomes. The student would 

 derive much advantage, in this respect, from placing 

 before him ten or a dozen species of insects very closely 

 resembling each other : such, for instance, as those com- 



