10 



DIRECT GROWTH OF VEINS BY SPROUTING. 



BIBLIOGRAPHY. 



Buell, C. E., 1922. Origin of the pulmonary vessels in the 



chick. Contributions to Embryology (this 



volume). 



Finley, E. B., 1922. The development of the subcutaneous 



plexus in the head of the human 



Contributions to Embryology (this 



vascular 

 embryo, 

 volume). 

 E., 1920. 



Holman, E., 1920. End-to-end anastomosis of the intestine 

 by presection sutures. An experimental study. 

 Johns Hopkins Hosp. Bull., vol. 31, p. 300. 



Huntington, G. S., 1911. The anatomy and development 

 of the systemic lymphatic vessels in the domestic 

 cat. Memoirs of the Wistar Institute of Anat- 

 omy and Biology, Philadelphia, No. 1. 



Kampmeier, O. F., 1922. The development of the anterior 

 lymphatics and lymph hearts in anuran embryos. 

 Amer. Jour. Anat., vol. 30, p. 61. 



Lewis, F. T., 1906. The development of the lymphatic 

 system in rabbits. Amcr. Jour. Anat., vol. 5, p. 

 95. 



Sabin, F. R., 1920. Studies on the origin of blood-vessels 

 and of red blood-corpuscles as seen in the living 

 blastoderm of chicks during the second day of 

 incubation. Contributions to Embryology, vol. 

 9, Carnegie Inst. Wash. Pub. No. 272. 



Stockard, C. R., 1915. The origin of blood and vascular 

 endothelium in embryos without a circulation 

 of the blood and in the normal embryo. Amer. 

 Jour. Anat., vol. 18, p. 227. 



Streeter, G. L., 1917. The development of the scala tym- 

 pani, scali vestibuli, and perioticular cistern in the 

 human embryo. Amer. Jour. Anat., vol. 21, p. 299. 



, 1918. The developmental alteration in the vascular 



system of the brain of the human embryo. Con- 

 tributions to Embryology, vol. 8, Carnegie 

 Inst. Wash. Pub. No. 271. 



Weed, L. H., 1917. The development of the cerebro-spinal 

 spaces in pig and in man. Contributions to 

 Embryology, vol. 5, Carnegie Inst. Wash. Pub. 

 No. 225. 



DESCRIPTION OF PLATE. 



Fig. A. Endothelial sprout from wall of median anterior vein of the area pellucida of the yolk-sac of a chick (No. 312) 

 on the fourth day of incubation. The specimen was grown on a cover-slip for 2 hours in Locke-Lewis 

 solution and then fixed in Bouin's solution, stained in hematoxylin and eounterstained in eosin and 

 orange G. X 525. 



Fig. B. Branched endothelial sprout from the wall of a smaller vein from the same specimen. The reticular structure 

 of the red blood-cells is an artefact due to the fixation. X 525. 



Fig. C. Small sprout from a vein, taken from the same specimen, showing a heaping up of endothelial nuclei at its 

 base. X 525. 



Fig. D. View of degenerating veins along the course of the same vein as figure 1, but closer to the embryo. The large 

 vein at the right is normal. The specimen shows the preliminary collapsing of the endothelium as 

 evidenced by the solid core of endothelium, followed by the death of both endothelial and adventitial 

 cells. X 525. 



