360 Mr. H. E. Strickland on the Structural 



II. We have next to consider that class of structural agree- 

 ments known by the name of Analogies. These consist in a 

 similarity of external form and of function connected with it, 

 but without that agreement of essence which constitutes Affi- 

 nity. These analogous agreements are equally the result of 

 natural laws, but of laws of a different class from the former. 

 Agreements of affinity are produced in conformity with the 

 laws of the organic Creation, while analogies have a reference 

 to the laws and properties of external and often inorganic 

 matter. In obedience to these laws, it follows that when- 

 ever an instrument is required to produce a given effect upon 

 external objects, or to resist their influences in a given manner, 

 there is in general one method, and one only, of effecting the 

 object in the best and most effectual way. Accordingly, what- 

 ever be the organ or instrument employed, that organ must 

 have a certain and definite mechanical structure bestowed 

 upon it to obtain the desired end. As a general rule, the 

 same end is attained in different organic beings by means of the 

 same set of organs ; but when those organs are required for 

 any other purpose, or are so modified as to be unfit for that 

 special end, then some other set of organs are endowed with 

 the requisite external structure and are called upon to act as 

 substitutes for the legitimate instruments. Examples of this 

 adaptation of organs to purposes remote from their normal 

 destination are numerous and well-known ; and I cannot do 

 better than refer to the late Mr. John Duncan's work on the 

 Analogies of Organized Beings, where there are numerous 

 examples of such analogies arranged in a tabular and highly 

 perspicuous form. We need only take the Elephant as an in- 

 stance. We may suppose that this animal required horns for 

 the purpose of defence, but it belongs to an order, the Pachy- 

 dermata, in which horns are uniformly absent, and the laws 

 of Affinity forbade their introduction. To supply this defect, 

 the incisor teeth are removed from their usual duties of mas- 

 tication, and are so developed as to assume the form and dis- 

 charge the function of horns. Further, the great size and 

 weight of these lengthened tusks required a great strength and 

 shortness of neck, and the animal was consequently unable to 

 reach the ground with his mouth. A hand was therefore re- 

 quired to convey the food to the mouth, but the vast weight 

 of the animal required a massive structure in the feet, which 

 forbade them to be adapted to the purpose of hands. To 

 supply this want then the nose is lengthened out, furnished 

 with muscles, divided at the end into a finger and thumb, and 

 in this proboscis behold a hand ! almost equal in delicacy of 

 manipulation to the hand of Man. And thus we see the Ele- 



