ON BIOLOGY. 21 



England, France, Italy, and elsewhere on the continent 

 In wonderful profusion. 



Morphology of vertebrates, other than man, was also 

 advanced most satisfactorily, and during the first thirty 

 years of this century a comprehension of the structure, 

 organization, physiology and composition of all organic 

 forms was fairly established, and as the years swept by 

 they were marked by an ever-increasing host of investi- 

 gators of all those departments, and by a most remark- 

 able giving-to-the-world of a perfect flood of literature 

 upon every branch of biology; not only those I 

 have just mentioned but also botany, palaeontology, 

 invertebrate zoology, man and all that refers to or con- 

 cerns him, pathology and psychology. This great wave 

 of intellectual activity swells up to the present hour 

 with a powerful augmentation of its force, propelled as it 

 is by the minds of an army of restless investigators, that 

 annually enlist a greater and a greater number of re- 

 cruits. So long, indeed, is this list of honored names, 

 that even to mention those who have distinguished them- 

 selves in the various departments of biology during the 

 time since the commencement of the present century 

 would be absolutely impracticable, as that list, with 

 even a reference to the principal works in each case, 

 would fill several goodly volumes. 



What have been some of the results of all this study 

 and investigation? They are not far to seek, but, as it 

 is my intention to revert to some of them more fully later 

 in the present course of lectures, only a few of 

 the main ones will be named in this connec- 

 tion. We saw that early in the history of the 

 biological sciences men but very slightly appreciated 

 either the unity of organization as it exists among plants 

 on the one hand, and animals on the other, or were 

 they scarcely at all aware of the mutual relations of the 

 biological sciences. Now modern science and research, 

 in the first place, has brought about a very thorough real- 

 ization of the interdependence of her various natural 

 divisions; and in the second place, the general uniformity 

 in the plan of structure of all animated beings is now 

 well known. 



Palaeontology and the microscope are largely respon- 

 sible for these results; the former demonstrating the rela- 

 tions of living things in geologic time, and the latter bring- 

 ing to light the agreement in kind of the few elements 

 or tissues throughout animated nature and out of which 

 all organic forms are composed and built up. 



