396 E. A. BAUMGARTNER 
Secammon (’11) in the normal plate series has figured the 
hypophysis in several of the younger stages. He described a 
distinct outpouching in 7.5 mm. embryos. In 18 mm. embryos 
a constriction of the anterior part of the hypophysis from the 
mouth has begun. In 24 mm. embryos shallow furrows sepa- 
rate two lateral portions from a median portion in the posterior 
part. A slight lateral constriction separates the anterior and 
posterior lobes. 
In 1912 Sterzi described the development of the hypophysis 
in Acanthias. He noted that the front wall of the outpouching 
becomes dorsal in later embryos. A rostral lobe develops which 
is in part anterior to the stalk connecting the hypophysis to the 
mouth. Two lateral outpouchings arise which later form the 
endocranial portion. The dorsal lobe develops at the superior 
end of the early outpouching. An early differentiation takes 
place in the cells of the dorsal lobe. Buds grow out from this 
thickened wall and form epithelial cords between which are blood 
vessels and nerve fibers. Differences in the affinity for stains 
distinguish the rostral (and endocranial) lobes from the superior 
which is the chromophobie lobe in adults. 
2. Anatomy and histology 
Von Michlucho-Maclay (’68) described in Acanthias and in 
Scymnus a persistent connection between the mouth and the 
hypophysis. In his later work (’70) this investigator failed to 
find such a connection and believed his former observations to 
be incorrect. 
Miiller (’71) found in later embryos and adults of Acanthias 
that the cells forming the glandular part are columnar while 
those toward the periphery of the cords and tubules are spindle- 
shaped, with a finely granular cytoplasm. He also noted the 
large capillaries and the connective tissue between the tubules. 
Viault (’76) briefly described the hypophysis in Raia. The 
hypophysis is surrounded by a connective tissue sheath which 
sends strands into the organ carrying large capillaries between 
the convoluted tubules. These tubules are 0.015 to 0.007 mm. 
