34 HISTOLOGY. 



In this manual you will find the tissue origin under 

 each tissue, as well as on this page. From the epiblast 

 or ectoderm are derived the following tissues : nerv- 

 ous tissue, the epithelium, covering the surfaces of 

 the body, the enamel, the nails, the hair, the organs of 

 special sense, and all glands, except those which open 

 into the alimentary tract, from the oesophagus down- 

 ward ; from the mesoblast or mesoderm are derived 

 blood, blood vessels, all the connective tissues, mus- 

 cles, dentine and cementum ; from the hypoblast or 

 hypoderm are derived the epithelial lining of the ali- 

 mentary canal and the glands opening into it. Tissues 

 may be placed into four groups : epithelial, muscular, 

 ncri'ous wid connective. 



