48 THE FUNCTIONS OF LIFE. 



But wherever that absolute necessity does not 

 exist, and there is afforded scope for deviation, 

 there we are certain to find introduced all those 

 modifications which the occasion admits of. Not 

 only is this tendency to variety exemplified in 

 the general appearance and form of the body, 

 but it also prevails in each individual organ, 

 however minute and insignificant that organ 

 may seem. Even when the purpose to be an- 

 swered is identical, the means that are employed 

 are infinitely diversified in different instances, 

 as if a design had existed of displaying to the 

 astonished eyes of mortals the unbounded re- 

 sources of creative power. While the elements 

 of structure are the same, there is presented to 

 us in succession every possible combination of 

 organs, as if it had been the object to exhaust 

 all the admissible permutations in the order of 

 their union. 



Some wise purpose, though dimly perceptible 

 to our imperfect understandings, is no doubt 

 answered by this great law of organic formation, 

 the law of variety. That it is not blindly or in- 

 discriminately followed, is apparent from its 

 being circumscribed within certain limits, and 

 controlled by another law, which we have next 

 to consider that of conformity to a definite type. 



The most superficial survey of nature is suffi- 

 cient to show that there prevail certain general 

 resemblances among great multitudes of species, 



