63 



LECTURE Y. 



Of Elementary Organs and Tissues Of the Functions 

 of Organs and Tissues Changes during Life Of 

 the Elementary Units Erroneous views on Cell- 

 Formation Formation of the Unit or Cell Formed 

 Matter Things essential to the Cell Nutrition of 

 an Elementary Part Of the increase of Cells 

 Cuticle Hair, Horn, Nail Epithelial Textures 

 hardened, with Calcareous Matter Enamel Den- 

 tine Dentinal il tubes" Of Secreting Cells 

 Different Products formed by the same Bioplasm 

 Fat - Cell Starch - Cell Secondary Deposits 

 Ciliated Cells Pigment Cells Salivary 



98. Elementary organs and tissues. The body of 

 the adult man or animal is made up of many different 

 organs, which perform very different offices. These 

 all derive the elements of their nutrition from the 

 blood, and are all under the control of the nervous 

 system. The nervous system consists of many dif- 

 ferent parts, but these are all connected by inter- 

 communicating cords or nerve fibres. Each organ is 

 composed of a great number of elementary organs 

 closely resembling one another, and so combined 

 that the work of all is united together. Every 

 elementary organ is made up of a variety of textures 

 differing from each other in appearance and struc- 

 ture, and in the offices they discharge. 



99. Tissues of a limb. If a transverse section be 

 made, for example, of the fore leg of an animal, we 

 find externally a texture which is well known to all 

 as the skin a tissue not simple in its structure, but 



