3 o SCIENCE PROGRESS 



physiology and pathology the great value of which they have 

 recognised though they have both experienced great difficulty 

 in learning how exactly to use it. These experimentalists 

 removed the pancreas from dogs and showed that its removal is 

 followed at once by a permanent condition of glycosuria. We 

 now realise fully that in the absence of some pancreatic function 

 the power to utilise sugar is completely absent from the tissues. 

 What exactly is the nature of that function ? In spite of much 

 endeavour the answer to this question is far from complete. 

 The general opinion, at any rate, is that it is exercised at 

 the seat of utilisation. An objective view is taken and 

 seems justified by experiment, that when an active tissue 

 element is to abstract energy from sugar, a tertium quid is 

 necessary to enable the former to get its chemical grip upon 

 the latter. This tertium quid is supplied in the internal secretion 

 of the pancreas and reaches the tissues by way of the blood. 

 Perhaps because scientific thought tends to run in ready-made 

 channels but also because of some experimental justification, 

 this view is made more definite by attributing to the pancreatic 

 factor the functions of an " amboceptor " — a conception and a 

 term derived from the literature of immunity. An amboceptor 

 is an agent which, by its ability to combine chemically with 

 each of two substances incapable of combining when alone, 

 completes a chemical system in such a way that the two sub- 

 stances are brought into interaction. - This is essentially a 

 definition of a catalyst but the action of an amboceptor has 

 certain quantitative relations, which I must not stop to define 

 more closely, which put it in a special class of catalysts. A 

 current conception is that the pancreatic amboceptor brings 

 some enzymic mechanism of the tissues into relation with the 

 sugar. Until quite lately, at least, the evidence seemed to show 

 that it was directly concerned with the breakdown of sugar. 

 Pavy, when he came, somewhat late in the course of his teach- 

 ing, to express views as to the influence of the pancreas, 

 accepted the term amboceptor but modified the conception of its 

 action in a manner which was characteristic. It is, according to 

 him, an agent necessary for assimilation ; only in its presence 

 can sugar be so linked on to bioplasm as to undergo ultimately 

 the necessary building up into the living complex of lymphocytes 

 or liver-cells. In this connexion he himself carried out experi- 

 ments which showed that when pancreatic extracts are injected 



