150 THE CANADIAN NATURALIST. [Vol. vi. 



been felt iu our own times to the progress of biological views and 

 thought ; and it is most satisfactory to observe the effect which 

 this influence is already producing on the scientific mind of this 

 country, in opposing the tendency perceptible in recent times to 

 the too restricted study of special departments of natural history. 

 I need scarcely remind you that for the proper investigation and 

 jndgmeut of problems in physiology, a full know^ledge of anatomy 

 in general, and much of comparative anatomy, of histology and 

 embryology, of organic chemistry, and of physics, is indispensable 

 as a preliminary to all successful physiological observation and 

 experiment. The anatomist again, who would profess to describe 

 rationally and correctly the structure of the human body, must 

 have acquired a knowledge of the principles of morphology de- 

 rived from the study of comparative anatomy and development, 

 and he must have mastered the intricacies of histological research. 

 The comparative anatomist must be an accomplished embryolo- 

 gist in the whole range of the animal kingdom, or in any single 

 division of it which he professes to cultivate. The zoologist and 

 the botanist must equally found their descriptions and systematic 

 distinctions on morphological, histological, and embryological 

 data. And thus the whole of these departments of biological 

 science are so interwoven and united that the scientific investiga- 

 tion of no one can now be regarded as altogether separate from 

 that of the others. It has been the work of the last forty years 

 to brins: that intimate connection of the biological sciences more 

 and more fully into prominent view, and to infuse its spirit into 

 all scientific investigation. But while in all the departments of 

 biology prodigious advances have been made, there are two more 

 especially which merit particular attention as having almost taken 

 their origin within the period I now refer to, and as having made 

 the most rapid progress in themselves, and have influenced most 

 powerfully and w^idely the progress of discovery, and the views of 

 biologists in other departments — I mean histology and embry- 

 ology. 



HISTOLOGY. 



I need scarcely remind those present that it was only within a 

 few years before the foundation of the British Association that 

 the su<>i>estions of Lister in res-ard to the construction of achro- 

 matic lenses brought the compound microscope into such a state 

 of improvement as caused it to be restored, as I might say, to the 

 place which the more imperfect instrument had lost in the pre- 



