I46 A. C. EYCLESHYMER AND J. M. WILSON. 



Explanation of Plate VI. 



Figures i-6 are magnified about 50 diameters ; figures 7-1 1 about 450 diameters. 



Fig. 1. Median sagittal section of the anterior portion of an embryo about seventy- 

 two hours after fertilization, showing the anlage of the adhesive organs. 



Fig. 2. Oblique sagittal section of anterior portion of embryo about ninety-five 

 hours after fertilization. 



Fig. 3. Transverse section through an embryo of same age, showing paired diver- 

 ticula of the foregut which become the adhesive organs. 



Fig. 4. Sagittal section of an embryo one hundred and ten hours after fertilization 

 showing median portion of the adhesive organs and the heart. 



Fig. 5. Obliquely transverse section of an embryo one hundred and twenty -five 

 hours after fertilization passing through the anterior margin of the adhesive organ on 

 one side and the optic stalk and vesicle on the other. 



