( 149 ) 



had lost the power to take up carbon, after being replaced in the 

 normal serum, over 50% of the phagocytes recovered their original 

 capacity. 



So, the greater part of the phagocytes can support a considerable 

 volume of water without permanent loss of their phagocytarian 

 capacity. 



Here may be asked: On what does it depend, whether a phagocyte will 

 regain its phagocytarian power? It is not impossible, nay, it is even probable, 

 that here as well as in the case of the red corpuscles some lose their contents 

 in serum diluted with 70 % of water 1 ). If the quantity of water added be raised to 

 100 "/„„ the number of destroyed erythrocytes will be found considerably larger. 

 When the red corpuscles, which have not lost their haemoglobin, are removed 

 from the serum diluted with 100°/,, of water into undiluted serum, they entirely 

 recover; they change from small globules into biconcave discs, which even arrange 

 themselves like piles of coins. 



However, this only applies to the cells which have not lost their colouring matter. 

 These which have actually lost haemoglobin cannot recover. Now our microscopical 

 investigations have revealed the fact, that in serum -j- 70 % water, some of phago- 

 cytes lose a part of their contents ; in that case we see a granular substance 

 lying by their sides. In serum to which 100 % water has been added, the effect 

 is more apparent stilk Then the number of leucocytes which have expelled granular 

 matter is still larger. It is easy to understand that these cells, when again placed 

 in normal serum, have lost the power of taking up carbon. The difficulty of 

 ascertaining this with certainty however,- is very great: in the transmission there is 

 every chance of disturbing the granular substance by the side of the cells, and it is 

 impossible to know whether one deals with a phagocyte which has lost part of its 

 contents or not. Anyhow, taking into consideration the striking analogy existing 

 between white and red corpuscles, both with regard to their permeability and to 

 the osmotic pressure of their interior substance, and even to the percentage of 

 the volume of their watery contents 2 ), we seem justified in our conjecture that the 

 same fluid, which causes a loss of colouring matter in the least resisting of red 

 corpuscles, also brings about the irremediate destruction of the phagocytarian 

 power of the least resisting phagocytes. 



It is a fact worthy of notice that the resisting power of the 

 phagocytes reaches a higher maximum than that of the erythrocytes. 

 In serum diluted with 200% water, all the erythrocytes of the horse 

 are destroyed, and not quite half of the phagocytes. 



III. Effect on phagocytosis by the reduction of water. 



A similar method as had been used for studying the effect on phago- 

 cytosis by dilution of the serum, was now applied to ascertain the 



') Hamburger. Transactions of the Royal Academy of Sciences, 26th March 1885. 

 ') Osmot. Druck u. Jonenlehre I, S. 401—435. 



