ADDRESS. lxix 



be wanting on my part ; and I must therefore at once bespeak their assistance 

 and your indulgence. 



I have selected for the subject of the remarks which I am about to offer 

 a biological topic, namely, the " Development of the Forms of Animal 

 Life," with which my studies have been occupied, and which has important 

 bearings on some of the more interesting biological questions now agitating 

 the scientific world. But before proceeding with the discussion of my 

 special subject, it is my desire to call your attention shortly to the remark- 

 able change in the manner of viewing biological questions which has taken 

 place in this country during the last half-century — a change so great, 

 indeed, that it can scarcely be fully appreciated except by those who, like 

 myself, have lived through the period of its occurrence. 



In the three earlier decades of this century it was the common belief, in 

 this country at least, shared by men of science as well as by the larger body 

 of persons who had given no special attention to the subject, that the various 

 forms of plants and animals recognized by naturalists in their systematic 

 arrangements of genera and species were permanently fixed and unalterable, 

 that they were not subject to greater changes than might occur as occasional 

 variations, and that such was the tendency to the maintenance of uniformity 

 in their specific characters that, when varieties did arise, there was a 

 natural disposition to return, in the course of succeeding generations, to 

 the fixed form and nature supposed to belong to the parental stock ; and it 

 was also a necessary part of this view of the permanency of species that each 

 was considered to have been originally produced from an individual having 

 the exact form which its descendants ever afterwards retained. To this 

 scientific dogma was further added the quasi-religious view that in the exercise 

 of infinite wisdom and goodness, the Creator, when He called the successive 

 species of plants and animals into existence, conferred upon each precisely the 

 organization and the properties adapting it best for the kind of life for 

 which it was designed in the general scheme of creation. This was the older 

 doctrine of "Direct Creation," of "Final Causes," and of " Teleological 

 Eelation of Structure and Function ; " and those only who have known the 

 firm hold which such views formerly had over the public mind can under- 

 stand the almost unqualified approbation with which the reasoning on these 

 questions in writings like the ' Bridgewater Treatises ' (not to mention older 

 books on Natural Theology) were received in their time, as well as the very 

 opposite feelings excited by every work which seemed to present a different 

 view of the plan of creation. 



On the Continent of Europe, it is true, some bold speculators, such as 

 Goethe, Ofcen, Lamarck, and Geoffroy St.-Hilaire, had, in the end of the last 

 and commencement of this century, broached the doctrine that there is in living 

 beings a continuous series of gradations as well as a consistent and general 

 plan of organization, and that the creation, therefore, or origin of the 



1877. / 



