50 FKEDERICK TILNEY AND LUTHER F. WARREN 



4. The development of the epiphyseal complex in teleosts 



Rabl-Riickhard 318 in 1882 gave the first explanation of the 

 development of the epiphyseal complex in teleosts. Hoffmann 185 

 in 1884 also described the ontogenesis of the pineal organ in 



44 



15 



14 



10 



"26 



33 



21 



Fig. 17 Mesial view of brain reconstruction in adult Mustelus laevis. X 25. 

 The unshaded area shows the cut surfaces of the reconstruction. According to 

 Tilney, 1915. 



2, chiasmatic process; 3, cerebellum; 4, chiasm; 6, diverticular sacci vasculosi; 

 7, epiphysis; 10, hypophyseal recess; 12, infundibular canal; 14, infundibular proc- 

 ess, saccular surface; 15, infundibular process, pituitary surface; 20, lamina ter- 

 minalis; 21, median chiasmatic groove; 24, midbrain; 26, mammillary recess (re- 

 cess of posterior lobe) ; 27, mammillary body (posterior lobe) ; 32, post-chiasmatic 

 eminence (inferior lobe) ; 33, post-chiasmatic recess (recess of inferior lobe) ; 34, 

 post-infundibular eminence; 35, post-infundibular recess; 39, paraphysis; 42, 

 supra-optic recess; 44, telencephalon; 47, velum transversum. 



teleosts. Both authors employed the same forms, namely, 

 Salmo fario and Salmo solar. According to their descriptions, 

 the anlage begins as a small evagination which gradually elon- 

 gates and grows more and more narrow. It has produced a 

 proximal portion, a stalk and an end- vesicle which lie just 

 beneath the inner surface of the skull in the frontal region. 



