[New York Academy of Sciences. Memoirs, Vol. II, Part II, pp 47 to 83, October 15, 1900.] 



KUPFFER'S VESICLE AND ITS RELATION TO GASTRULATION AND 



CONCRESCENCE. 



FRANCIS BERTODY SUMNER. 



(Read February 12, 1900.) 



[Text figures 1-34 ] 



CONTENTS. 



PAGE 

 INTRODUCTION 



I. THE TELEOST GASTKULA 48 



Gotte's view 



A new factor 50 



II. KUPFFER'S VESICLE 52 



The prevailing view 52 



Relation of Kupffer's vesicle to the " Prostomal thickening" 53 



Kowalewski's account of Kupffer's vesicle 53 



Conclusive evidence of the preceding view 54 



Previous observations of a similar nature 55 



Condition in Amia 57 



III. RELATION OF PROSTOMA TO GERM LAYERS 59 



Prostomal thickening and gut-hypoblast 59 



The relation of the gut epithelium to the notochord 60 



Historical 61 



IV. SIGNIFICANCE OF PROSTOMAL INVAGINATION 62 



V. CONCRESCENCE AND CONFLUENCE 68 



Problem stated 68 



Experiments of Morgan and Kopsch '. 70 



Conclusions 72 



VI. FURTHER MORPHOLOGICAL CONSIDERATIONS 73 



VII. YOLK VESICLES 74 



VIII. THE FUNCTION OF KUPFFER'S VESICLE 76 



IX. RECAPITULATION 77 



X. NOTE ON METHODS 78 



XI. SUPPLEMENT 79 



BIBLIOGRAPHY.... 80 



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