No. 6.] 



THE HYPOPHYSIS IN CHELONIA. 



277 



PLATE I. 

 Ect.Endj Pa. 



/ /' 



FIG. i (PI. I), Stage A. Combination diagram formed from the six sections 

 nearest to the median sagittal section. Embryo of Chrysemys marginata. 

 Mesoblastic somites = 5^. Lg. of embryo = 2.5 mm. x 62. 



FB.' 



FIG. 2 (PI. I), Stage B. Diagram of the median sagittal section of an embryo 

 of Aspidonectes spinifer. Lg. = 5.2 mm. Mesoblastic somites = 21. x 50. 



