2 THE HUMAN BODY. 



constituent parts, as eyes, nose, ears, mouth; arm, fore- 

 arm, hand; thigh, leg and foot. We can, with such 

 an external examination, go even farther and recognize 

 different materials as entering into the formation of the 

 larger parts. Skin, hair, nails and teeth are obviously 

 different substances ; simple examination by pressure 

 proves that internally there are harder and softer solid 

 parts; while the blood that flows from a cut finger shows 

 that liquid constituents also exist in the Body. The con- 

 ception of complexity which may be thus arrived at from 

 external observation of the living, is greatly extended bv 

 dissection of the dead Body, which makes manifest that it 

 consists of a great number of diverse parts or organs, whict 

 in turn are built up of a limited number of materials; the 

 same material often entering into the composition of many 

 different organs. These primary building materials are 

 known as the tissues, and that branch of anatomy which 

 deals with the characters of the tissues and their arrange- 

 ment in various organs is known as Histology; or, since ifc 

 is mainly carried on with the aid of the microscope, as 

 Microscopic Anatomy. If, with the poet, we compare the 

 Body to a house, we may go on to liken the tissues to the 

 bricks, stone, mortar, wood, iron, glass and so on, used in 

 building; and then walls and floors, stairs and windows, 

 formed by the combination of these, would answer to ana- 

 tomical organs. 



Zoological Position of Man. External examination of 

 the human Body shows also that it presents certain re- 

 semblances to the bodies of many other animals: head 

 and neck, trunk and limbs, and various minor parts enter- 

 ing into them, are not at all peculiar to it. Closer study 

 and the investigation of internal structure demonstrates 

 further that these resemblances are in many cases not su- 

 perficial only, but that our Bodies may be regarded as built 

 upon a plan common to them and the bodies of many 

 other creatures: and it soon becomes further apparent 

 that this resemblance is greater between the Human Body 

 and the bodies of ordinary four-footed beasts, than between 

 it and the bodies of birds, reptiles or fishes. Hence, from 



