PHAGOCYTOSIS 2QQ 



The effects of surface tension may also be traced in some of 

 the phenomena of inflammation, especially in the adhesion of the 

 leucocytes to the vessel wall. It has been abundantly shown 

 that this is due to an alteration in the latter, and it appears likely 

 that this is simply due to a change in the tension developed at 

 the surface between the endothelial lining and the serum, in 

 virtue of which the former behaves like the glass in Ponder's 

 method, attracting the leucocyte and causing it to adhere and 

 flatten itself out. This extension, so as to offer as large a surface 

 as possible, which is displayed by the leucocytes, and especially 

 of the polynuclears, when they come into contact with a resistant 

 surface, was noted long ago by Massart and Bordet, and in virtue 

 of it they are able to make their way through the finest pores, 

 even in compact bodies like bone and ivory. The remarkable 

 deformation in shape which leucocytes undergo in acutely inflamed 

 tissues is not usually appreciated. It was pointed out to me by 

 Whitfield, and may often be seen at the edge of the sections 

 where the fixation is perfect, provided the material has been 

 placed in the fixing fluid immediately after its excision. The 

 polynuclear leucocytes are often overlooked altogether, being 

 pulled out into long strands of protoplasm containing nuclear 

 filaments, giving the section a remarkable mossy appearance. 

 This change in the surface tension of the vessels, lymph clefts, 

 etc., probably plays a part of great importance in diapedesis. It 

 is somewhat doubtful, however, whether it can afford a complete 

 explanation of the phenomena of chemotaxis, in which a vital 

 and apparently quasi-intelligent action appears probable. 



It must not be imagined that the vitality of the leucocyte is to 

 be regarded as unimportant in the consideration of phagocytosis 

 as a means of defence. Here the process has only begun when 

 the organism is ingested, and unless suitable digestive ferments 

 are secreted, the bacterium dissolved, and the endotoxin absorbed 

 or otherwise dealt with, the process is useless, or, by carrying 

 bacteria out of the lesion to other parts of the body, may even be 

 harmful. 



