14 
J. T. CUNNINGHAM. 
EXPLANATION OF PLATE I. 
Illustrating Mr. J. T. Cunningham’s memoir on “ The Signifi- 
cance of Kupffer’s Vesicle, with remarks on other Questions 
of Vertebrate Morphology.” 
Letters or Reference. 
Bl. Blastopore. Bp. Epiblast. Gc. Gastrula-cavity. My. Hypoblast. 
In. Infundibulum. Ev. Kupffer’s vesicle. Me. Mesenteron. Mes. Meso- 
blast. Ne. Neurochord. Ot. Otocyst. No. Notochord. Be. Periblast. 
Tk. Yolk. 
Pig. 1. — Embryo of herring fifty-four hours after fertilization. Obj. A oc. 
3, Zeiss. 
Fig. 2. — Section of a herring’s embryo at stage represented (fig. 1). All 
the sections were cut perpendicular to both ends of the embryo. The figure 
gives a section of the posterior part of the embryo taken near the extremity. 
Fig. 3. — More anterior section of the same series, passing through Kupffer’s 
vesicle. 
Fig. 4. — Section a little more anterior of the same series. 
Fig. 5. — From a herring’s embryo, sixty-three and a half hours after fertili- 
zation, about the region where Kupffer’s vesicle was at the previous stage. 
Fig. 6. — Section passing through otocysts, same stage as fig. 5. 
Fig. 7. — Herring embryo sixty-two and a half hours after fertilization. 
Fig. 8. — Diagram of a section through the plane of symmetry of a herring 
embryo at the stage of Kupffer’s vesicle. 
Fig. 9. — Diagram of a section through the plane of symmetry of a frog 
embryo at the stage corresponding to that of the Teleostean in fig. 8. 
N.B. — All the sections were drawn with the same lenses, the outlines by 
means of Abbe’s camera lucida. The scale of y^tli mm. is given in the 
plate. 
