DEVELOPMENT OF VESSELS WITHOUT HEART 203 



4, The general conclusion seems justified that, while certain 

 large vessels such as the sinus terminalis and the anterior vitel- 

 line veins develop as a result of hereditary factors, and continue 

 a normal development for a short time after the circulation starts, 

 'self-differentiation' of the vascular system is very limited, and 

 the working out of most of the arteries and veins is dependent 

 upon the mechanical factors concerned with the circulation of 

 the blood. 



I am indebted to Professor Eliot R. Clark for the assignment 

 of this problem and valuable instructions during its investigation. 



LITERATURE CITED 



Knower, H. AIcE. 1907 Effects of early removal of the heart and arrest of the 

 circulation on the development of frog embryos. Anat. Rec, vol. 1. 



LiLLiE, F. R. 1908 The development of the chick, H. Holt & Co., New York. 



LoEB, J. 1893 i'ber die Entwickhing von Fischembryonen ohne Kreislauf. 

 Pfluger's Archiv, vol. 54. 



Patterson, J. T. 1909 An experimental study on the development of the vas- 

 cular area of the chick blastoderm. Biol. Bull., vol. 16, pp. 87-88. 



PopoFF, Demetrius 1894 Die Dottersack-Gefasse des Huhnes. Wiesbaden. 

 (Reference in "The Development of the Chick," Lillie, 1908.) 



Roux, W. 1878 liber die Verzweigungen der Blutgefasse des Menschen. Je- 

 naische Zeitschr. f. Naturw., vol. 12, pp. 205-206. 



1895 Gesammelte Abhandlungen, vol. 1, p. 83, note. 



Sabin, F. R. 1917 Origin and development of the primitive vessels of the chick 

 and of the pig. Monograph. Contributions to Embryology, No. 18, 

 Carnegie Institute, of Washington. 



Stockard, C. R. 1906 The development of Fundulus heteroclitus in solution 

 of lithium chlorid, with appendix on its development in fresh water. 

 Jour. Exp. Zool., vol. 3, pp. 99-120. 



1915 The origin of blood and vascular endothelium in embryos with- 

 out a circulation of the blood and in the normal embryo. Am. Jour. 

 Anat., vol. 18. 



Thoma, R. 1893 UntersLichungen iiber die Histogenese und Histomechanic 

 des Gefiisssystems. Enke, Stuttgart. 



1896 Text-book of general pathology and pathological anatomy. 

 Translated bv Bruce, London. 



