PLATE 12 
Fig. 3. Cross-section of myelencephalon of 21.5 mm. embryo of 
Lepisosteus osseus, showing ‘‘anlage’’ of myelencephalie gland. X 112. 
Fig. 4. Cross-section of myelencephalon of 55 mm. embryo of Lepi- 
sosteus osseus, showing further development of myelencephalie gland. 
x 85. 
ABBREVIATIONS 
bas. art.—basilar artery. 
bl. sin.—blood sinus. 
cart.—eartilage. 
conn, tiss. n.—econnective tissue network. 
epend.—ependyma., 
eryth.—erythroeytes. 
med.—medulla oblongata. 
pig.—pigment cell. 
ith vent.—tfourth ventricle. 
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