278 Vertebrate Embryology 



1. Growth of the allantois. 



2. Growth of the limbs, and the appearance 

 in them of the cartilages and of the elbow-and 

 knee-joints. 



3. Appearance of the cartilaginous cranium, 

 and of the bars of cartilage in the visceral 

 arches. 



4. Development of parts of the face. 



5. Completion of the ventricular septum ; 

 and the appearance of the septum of the bul- 

 bus arteriosus, and of the semilunar valves. 



6. The establishment of the different tissues. 



