75 



Fig. 7 



Fig. 6 



Fig. 8 



Fig. 9 



Figs. 6 to 9. Fig. 6. — Leucocytes sending forth processes which penetrate 

 the wall of the vessel. Fig. 7. — Leucocytes partly through vessel wall, showing 

 constriction in centre. Fig. 8. — Leucocytes after penetrating wall regain former 

 shape. Fig. 9. — Appearance of vessel and surrounding tissue after diapedisis has 

 gone on for some time. (After Craig). 



Blood. Ca-pillary. 



Fig. 10. — Diagrammatic Representation of the Manner in which a Leucocyte 

 Traverses the Wall of a Capillary Blood- Vessel. (After Craig), a, Leucocyte 

 before penetrating ; J, leucocyte sending off process and granules beginning to 

 withdraw to farther end of cell ; c, leucocyte partly through wall, granules at 

 upper end of cell ; d, granules passing through the wall ; e, granules arranged 

 in the portion of the leucocyte farthest from vessel ; /, leucocyte, after pene- 

 tration, resuming its original condition ; g, leucocyte swept from wall, showing 

 retention of the clear penetrating process. 



