THE ONTOGENESIS OF VERTEBRATES 75 



hyoid and branchial arches, including the 

 muscles of the larynx. 



IV. Mesenchyme Connective tissues; including those in the 



strict sense, also cartilage and bone, and 

 the corium. Involuntary muscles of the 

 viscera and of the skin. 



Vascular system ; including heart, blood-vessels 

 and blood; lymphatics; and the septum of 

 the diaphragm. 



