Inflammation and Fever. 



white blood-cells, which have escaped from the vessels in the 

 adjacent vascular tissue and made their way into the in- 

 flamed and softened cornea. 



Thns in both types of inflammation, in the vascular and 

 non- vascular tissues alike, there is this abundant concentra- 

 tion of plastic cells (white blood-cells and tissue nuclei), 

 which assume for the time the functions of the cells of the 

 early embryo from which all the varied tissues of the future 

 animal are to be developed. Hence these cells, which 

 grow so abundantly in inflamed parts with the size, form, 

 and functions of embryonic cells, are not inaptly called em- 

 bryonic cells, and the tissue, which they first form, embry- 

 onic tissue. These cells may be looked upon as the guardi- 

 ans of the system, charged with the duty of removing from 

 the part all noxious, useless, or extraneous matter, and build- 

 ing up new tissue to repair the breach resulting from the 

 injury. E"© sooner is the injury sustained than there is es- 

 tablished an increased flow of blood through the vessels of 

 the injured part (or through the nearest blood-vessels in 

 case the injured structure has no vessels), the white globules 

 are delayed in the capillary vessels and passed through their 

 walls, and at the same time the tissue nuclei increase in size 

 and immbers, abandon their habitual work of building up 

 tissue, and together with the wandering blood-cells devote 

 ever^' power to the removal of the irritant and the repair of 

 the breach. A similar work is effected in an entirely natu- 

 ral way in the tail of the tadpole when developing into a 

 frog. Embryonic or lymphoid cells increase enormously in 

 the tail, feeding upon the tissues of the now superfluous 

 organ, and gradually absorbing and removing the whole 

 mass. So it is, too, in the case of offensive living organisms 

 introduced into a tissue. When bacteria have been thus in- 

 oculated inflammation is at once set up, and the accumulat- 

 ing cells, if numerous enough relatively to the micro-organ- 

 ism, take the bacteria into their substance and gradually 



