360 G. HAROLD DREW 



the condition of venous engorgement and stasis that occurs when 

 a septic tissue is implanted (Drew and De Morgan '10). 



After a time fresh blood corpuscles penetrate the thin agglu- 

 tinated layer, and start a phagocytic action on the ovarian tissue. 

 Meanwhile the fibroblasts in the walls of the blood spaces, and in 

 the intermuscular connective tissue in the neighborhood, undergo 

 division. This division is amitotic, and commences about twelve 

 hours after the implantation. Before division the fibroblasts 

 lose their spindle shape and become oval: a split then appears at 

 one end, and progresses in the plane of the long axis of the nucleus 

 until two daughter nuclei are formed, attached to each other at one 

 extremity, and inclined at an acute angle to one another. These 

 gradually straighten out until the}^ form an hour glass shaped 

 mass of nuclear material. Finally the two nuclei are separated 

 at the constriction, and two oval or circular cells are produced, 

 having large nuclei with relatively very little cytoplasm, and 

 bearing no resemblance to the spindle shape of a resting fibro- 

 blast. 



There follows a migration of these cells with round and oval 

 nuclei towards the site of the implantation. They chiefly follow 

 the course of the strands of fibrous tissue bounding the blood 

 spaces, but many migrate in all directions between the muscular 

 fibres. 



On reaching the layer of agglutinated corpuscles surrounding 

 the implanted tissue, the fibroblasts arrange themselves in rows; 

 and their nuclei elongate in such a direction that their long axes 

 form arcs of a circle surrounding the implanted ovary. 



This surrounding layer presents a somewhat stratified appear- 

 ance. At first it contains a number of blood-corpuscles, but these 

 eventually are removed, probably by autolysis, leaving only the 

 fibroblasts. 



In these experiments the layer of fibrous tissue formed in this 

 way was always very slight, usually not more than two or three 

 cells thick. If by any error sepsis occurred, it was followed by a 

 violent inflammatory reaction, and if the animal survived, by 

 subsequent great formation of fibrous tissue. 



Meanwhile the implanted ovarian tissue shows signs of degen- 



