34 THE PHYSIOLOGY OF PROTEIN METABOLISM 



of the action of the leucoctyes. Pavy (324) held that the whole con- 

 version of the food protein into tissue protein was brought about by the 

 lymphocytes. He maintained that the products of protein digestion 

 were resynthetized at the seat of absorption by the lymphocyte growth 

 and that the lymphocytes in turn were resolved by autolysis into the 

 proteins of the blood and in this way the fresh food material was 

 brought within reach of the tissue cells, in other words he believed, like 

 Abderhalden, that the proteins of the blood formed the pabulum for the 

 tissue cells. 



None of these workers, however, support their hypothesis by any 

 observations on the variation in constitution of the leucocytes before and 

 after a meal. There is no doubt about the postprandial leucocytosis, 

 but it is not yet proven that these leucocytes are engaged in the manu- 

 facture of the new food for the tissues. Halliburton (i 64) has offered an 

 excellent criticism of the leucocyte synthesis theory. He pointed out 

 that the number of the lymphocytes available was not commensurate 

 with the work to be done. He calculated that a man of eighty kilos 

 had about four kilos of blood of which some forty per cent, was 

 in the form of corpuscles, that is about 1600 grams. Now as the ratio 

 of white corpuscles to red is about I : 500 it means that about yz 

 grms. of leucocytes are present. Of this amount lymphocytes form 

 at most thirty per cent., and therefore in the blood there would be 

 about one gram of lymphocytes. If this amount were doubled 

 during digestion, "it is difficult to see how two grams of lym- 

 phocytes can tackle the enormous burden which every meal must 

 impose upon them ". Even using the figures of Gulland, who stated 

 that the rise in the number of leucocytes might be as much as four 

 times, the difficulty in ascribing so large a synthetic action to this 

 comparatively small number of white cells is great, more particularly 

 if, as Pavy supposed, the newly formed protein was liberated by a 

 complete autolysis of the cell in which the synthesis took place. 



