18 president's address. 



potent help of the microscope, or by the assistance of mechanical 

 or chemical means, the processes involving much time, labour, 

 and thought. 



The internal structure, as well as the external form and pro- 

 perties of natural bodies, claims our investigation ; a knowledge 

 of both is required to enable us to understand the adaptation of 

 the creature to the world around it, and to determine its true 

 position in the scale of life ; the former is more important indeed, 

 than the latter, and is that which more particularly characterizes the 

 organism, and on which its properties and manifestations mainly 

 depend. It is a much easier task to assemble and group living 

 animals according to external characters only, and in that path 

 undoubtedly much of detail has been successfully worked out ; but 

 the masters of Natural History have, ever since the great enuncia- 

 tion, " the blood is the life," betrayed their consciousness of the 

 high value of internal structure as a basis of classification. 



Aristotle arranged all animals as Anaima or Enaima, or those 

 with and those without blood : after his time it was found more 

 in accordance with nature, to class, under the former of these 

 names, the animals with colourless blood, and under the lattor 

 those with red blood. The genius of Lamarck seized upon the 

 vertebral or spinal column, as a standard, and, at once, the whole 

 of the animal scale stood ranged in two great sub-divisions. 



Cuvier more recently perceived the paramount importance of 

 the nervous system, and this enabled him to divide Lamarck's 

 Invertebrata into three sub-kingdoms. 



Since the time of Lamarck, Cuvier, and Hunter, the importance 

 of the internal structure of animals has been more fully acknow- 

 ledged, and hence our science has progressed with increasing- 

 rapidity. The ignorance of the necessity of the combined study 

 of internal structure and external character continues however, 

 up to the present time, to be evidenced by the hosts of imperfect 

 arrangements which have been promulgated to the confusion and 

 despair of the student, and which are monuments of human 

 ingenuity and impatience. It must, however, be a source of pride 

 to us that the true method of study has been so clearly and so 

 successfully illustrated as it is in the first volume of our Tran- 



