IV.J 



THE VASCULAR SYSTEM. 



93 



points, blood-corpuaolea make their appearance in the pro- 

 cesses also,, the central poi-tions of which become at the same 

 time liquefied. 



By the continued widening of the connecting processes and 

 solution of their central portions, accompanied by a corresponding 

 increase in the enveloping nucleated cells, the origiaal proto- 



FiG. 33. 



Surface View prom below of a small portion op the 

 Posterior End op the PELLnciD Area op a Thirty-six 

 hours' Chick. To illustrate the formation of the blood- 

 capillaries and blood-corpuscles, magnified 400 diameters. 



b.c. Blood-corpuscles at a nodal point, already beginning to 

 acquire a red colour. They are enclosed in a layer of proto- 

 plasm, in the outermost part of which are found nuclei, a. 

 These nuclei subsequently become the nuclei of the cells 

 forming the walls of the vessels. The nodal groups are 

 united by protoplasmic processes (jp.pr), also containing 

 nuclei with large nucleoli (w). 



