166 LECTDEES. 



the body, still the same differentiation of form and specialization of 

 iuction is observable as we pass from the embryonic to the mature 

 condition, or from the lowest to the highest animals. I might give 

 many other examples taken from the organic kingdom. I will give 

 bat one other example, and that taken from a still higher kingdom. 

 Human society is also an organized body, the ultimate anatomical 

 elements of which are individuals. Now, in the earliest conditions of 

 human society we find these elements, so far as their social functions 

 are concerned, identical. Each man performs all the social functions 

 apertaining to man. He is his own tailor, shoemaker, agriculturist, 

 scientific man, &c. But in proportion as society advances in the same 

 proportion does specialization of social functions advance, until, if we 

 could conceive of a society perfectly organized on a purely material 

 basis, i. e. according to the French material philosophy, then the 

 social function of each individual would be reduced to the narrowest 

 possible limits. This is only impossible or undesirable on account of 

 man's moral and spiritual nature. Still it is no less evident that, in 

 f-o far as human society is a material organization, specialization of 

 lunction, differentiation is the law of development. 



Now, it will be recollected that in the geological history of animals 

 and plants we have everywhere found the same differentiation of form 

 and specialization of function. As in the history of the animal body, 

 one cell form in the embryo was the representative of many widely 

 separated cell forms in the mature animal ; so also in the geological 

 liistory of that greater and more complex organism, the animal and 

 vegetable kingdom, one form in the early periods stood as the repre- 

 sentative of many widely separated forms in its present mature con- 

 dition. Am I not justified, then, in saying that the great law which 

 has governed the introduction of successive animal and vegetable spe- 

 cies is that of gradual development of the animal and vegetable king- 

 dom as an organic luliolef 



It seems to me that all the dispute and misunderstanding on this 

 subject have been the result of too narrow a view, have arisen from fixing 

 the mind upon genera and species instead of upon the larger divisions 

 of classes and orders, upon the individual elements instead of the 

 organic whole. Development does not necessarily involve the idea of 

 ])rogression in all the individual elements. In the differentiation of 

 the cells of the living body, of the individuals of an advancing com- 

 munity, or of the forms of an advancing fauna, the whole organism 

 progresses, but as a necessary result of differentiation, while the high- 

 est individuals are successively higher and higher, the lowest, consid- 

 ered in themselves, and not as parts of an organized whole, may 

 hecome loiver. Certainly the difference between the high and the low 

 becomes constantly greater. It should not surj^rise us, then, that 

 f^ome of the lowest torms of animal life have been among the latest 

 introduced. It is precisely what, according to a true appreciation of 

 the law of development, we should be naturally led to expect. 



Mr. Plugh Miller, the eminent Scotch geologist, in his admirable 

 work, " Footprints of the Creator," by taking too limited a view of 

 this subject_, has been led, if not into error, at least into a statement 

 of views which has misled many. In his zeal against the Lamarck- 



