472 MORGAN. 



EXPLANATION OF PLATE XXV. 



Figs. 31-38. Ctenolabrus. 



Fig. 31. Embryo, abnormal, from sea-water diluted by fresh-water. 



Fig. 32. 



Fig. 33- 



Fig. 34. Same. Without differentiation of embryo. 



Fig. 35. Same. Tail-knob projecting. 



Fig. 36. 



Fig. 37. Embryo with one side of germ-ring undeveloped. Posterior end. 



Fig. 38. Anterior end of last. 

 Figs. 39-40. Fundulus. 



Fig. 39, A-C. A, young embryo. Germ-ring cut at right side. B, later 

 stage of last; C, same, showing full length of embryo. 



Fig. 40, A, B. A, young embryo. Germ-ring cut at left side. B, later 

 stage of last. 

 Figs. 41-43. Ctenolabrus. 



Fig. 41. Cross-section through middle of Fig. 32. 



Fig. 42. " " embryo of Figs. 37, 38, passing through 



posterior end of body (six sections in front of Kupffer's vesicle). 



Fig. 43. Section through ring of Fig. 34. 



