THE PINEAL BODY 



79 



striking characteristics as to make it one of the most prominent 

 and important elements in the epiphyseal complex. Its appear- 

 ance in cyclostomes is almost as striking as the pineal end- vesicle, 

 but its tendency to irregularity is noted by a complete absence 



P.M. 



OC. 



Fig. 11 Reconstruction showing the development of the pineal region of a 

 sheej. embryo of 48.4 mm., according to John Warren, 1917. 



FM ., foramen of Monro; P., paraphysis; V., velum; S.C., commissura haben- 

 ularis; E., cpiphysis; P.C., posterior commissure. 



