TJHI7BRSIT7 



THE 



SCIENCE OF LIFE. 



CHAPTER I. 



WHAT IS LIFE? 



Am I but what I seem mere flesh and blood ? 

 A branching channel, and a mazy flood ? 

 The purple stream that through my vessels glides, 

 Dull and unconscious flows, like common tides. 

 The pipes, through which the circling juices stray, 

 Are not that thinking I, no more than they. 

 This frame, comparted with transcendent skill, 

 Of moving joints, obedient to my will, 

 Nursed from the fruitful glebe, like yonder tree, 

 Waxes and wastes : I call it mine, not nit. 

 New matter still the moldering mass sustains, 

 The mansion changed, the tenant still remains ; 

 And from the fleeting stream, repaired by food, 

 Distinct, as is the swimmer from the flood. 



ARBUTHNOT. 



i. THE term Biology, (from the Greek, bios, life, and 

 logos, a discourse, or doctrine,) signifies the Science of 

 Life. It includes the study of all the phenomena of living 

 beings, both animal and vegetable, in order to discover 

 the general principles which underlie their origin, for- 

 mation, varieties, and functions. The special study of 

 structure is termed Morphology, or Anatomy. The 

 study of functions is Physiology. The origin, develop- 

 ment, and arrangement of the varieties of the vegetable 

 world make up the study of Botany. Zoology considers 



