IN RELATION TO ORGANISED BEINGS. 35 



latitude' as not being all absolutely found in all tbe members. All 

 organised structures are more or less complicated, the very simplest 

 affording various points of resemblance and difference with other 

 structures, whilst degrees of complication themselves afford valuable 

 assistance in grouping ; but to give our studies the most interesting 

 and instructive character, we must find out what kind of particulars 

 are most essential in respect to living structures, what is the apparent 

 meaning in respect to the general condition of the organism of differ- 

 ences observable between one and another, and with what kind of 

 variations, or in regard to what class of circumstances the elevation or 

 depression of the organism in the scale of being is most specially con- 

 nected. If we could not obtain some clear conception of what is 

 common to all living organisms, and enumerate the several distinct 

 kinds of action or of progressive change by which the condition of all 

 beings is made to be what it is perceived to be, we should have no 

 foundation for any better classification of objects than might be formed 

 by the arbitrary choice of any obvious particular of agreement and 

 difference which might assist us in distinguishing and remembering 

 the objects, but could answer no higher purpose. Hence, until life 

 had been so studied that we could see what is common to the whole 

 and to extensive sections of organised beings, could distinguish essen- 

 tial functions and different modes of performing them, and form rules 

 for throwing classes of organisms into series ranging from the lowest 

 to the highest, we could not possess any means for forming a natural 

 classification which should be the expression of the real plan of nature, 

 the actual relations of all beings to each other and to the system of 

 the universe. If there were really no sufiicient marks of an harmo- 

 nious order and general plan in nature ; if organised beings were 

 found to be in a state of transition from one form and condition to 

 another, and vital functions were performed in different ways accord- 

 ing to changing circumstancps, then indeed the pursuit of natural 

 systems of arrangement would be vain and useless, and we might as 

 well be content with any plan, however artificial, which would assist 

 us to record and apply our observations on the objects around us. 

 But we are authorised to hope for better things : there are great 

 natural divisions indubitably established as expressing, not human 

 contrivances for assisting study, but natural associations of objects 

 whose real connection is clearly perceived by the mind which has 

 been brought to the knowledge of the actual condition of things, and 



