The Leucocytes in Aiucinias. i6i 



place here and there in the vessels, occlusion of the capillaries 

 and serious lesions of the renal epithelial cells. 



Oligsemia is occasionally associated with a truly watery condition of 

 the blood, as where in case of haemorrhage, blood imiioverishment, inani- 

 tion, or renal disease the blood becomes deficient in albumen, the vessels 

 become filled with the fluid from the tissues in an effort to restore the 

 deficiency; such a condition is termed hydrccntia (oligccniia serosa). So. 

 too, the increase in the proportion of water with increase of the total 

 volume of blood (plethora aquosa. serosa) may lie thought of as a 

 pathological possibility; however, proper information is as yet lacking 

 concerning these pathological conditions and the relation between quanti- 

 tative changes of the serum albumen to the proportion of water in the 

 blood. Normally, large excesses of water known to be rapidly absorbed 

 from the stomach and intestine into the blood are quickly passed off 

 through the kidneys. 



Of the pathological conditions of the leucocytes or white blood 

 cells and their reduction or increase in numbers in the circulating 

 blood our knowledge is only of the most superficial character. 

 To what extent the morphological and tinctorial peculiarities of the 

 individual forms and groups of leucocytes and lymphocytes nor- 

 mally found in the blood are characteristic of the origin and of the 

 role of these cells is a matter requiring further investigation. 

 These cells are of especial interest to the pathologist from the fact 

 that they are either attracted or repelled by chemical materials in 

 the tissues and by various particulate elements which may give 

 origin to the former (positive and negative cheinotaxis). Be- 

 cause of the power possessed by these cells of approaching or 

 receding from a given point like motile organisms, of taking into 

 their substance small bodies which they encounter — an act which 

 is to be regarded as an attempt to obtain nourishment (cellular 

 devouring capacity, pliogoeytosis) — they may be thought of as 

 playing the part of "scavengers of the organism"' (products of 

 disintegration, dust particles, dead cells and tissues, dead bacteria, 

 etc., all being removed in this manner). They may however by 

 identically the same mode of action come to serve as carriers of 

 infection in case a living bacterium or animal microorganism hap- 

 pen to be taken up by them. A microorganism not necessarily 

 destroyed in the substance of the leucocyte, but possibly actually 

 multiplying there, may be carried away to a new situation and 

 there renew its toxic influences, especiall\" if the phagocytic cell be 

 destroyed by its poison. [.Metschnikofif urges strongly that after 

 appropriation of a microbe by a phagocyte, the former may be 



