152 GENERAL BIOLOGY. 



fully remove from the salt solution, and exam- 

 ine with a hand-lens and with A A 2. 

 Study at first the circulation, the gill-slits, 

 and the movements of the heart. Then 

 review as far as possible the general 

 anatomy. 

 VII. The Fourth Day. 



1. The formation of the face. 

 With a razor cut off the head dose "behind the last 

 gill-slit. With fine forceps remove the parts 

 of the heart, etc. , that are attached to the gill- 

 region. Fix the head, dorsal side down, in a 

 small dish of alcohol, and with a hand-lens 

 study and sketch the ventral and lateral 

 aspects. 

 Find: 



(a) The naso-frontal process. 

 (6) The nasal pits. 



(c) The eyes. 



(d) The mouth. 



(e) The superior maxillary process. 

 (/) The visceral arches. 



What structures are visible in section on the 



cut surface. 

 Till. Older Stages. 



Examine for the amnion and the allantois, 



and for the development of the face, the 



limbs, and the feathers, and for the changes 



of the yolk-stalk. 



