SECT. 8] CARBOHYDRATE METABOLISM 



Blood sugar in mgm. % 



1041 



Investigator 

 Olow 

 Rowley 

 Hellmuth ... 



Morriss 

 Bergsma 



Species 

 Man 

 Man 

 Man 



Man 

 Man 



Foetal 



80 



90 



Maternal 



Foetal blood sugar always lower than 

 maternal by 9-84 mgm. % 



115 132 



Foetal blood sugar the same as maternal at birth 



These will be dealt with in detail in the Section on placental permea- 

 bility. At present we must neglect the apparently regular changes 

 in Aron's data and assume, with him, that the embryo is able to 

 regulate its own blood sugar, for that was the point on which he laid 

 special emphasis. "Le miheu interieur du foetus", he said, "reste, 

 au point de vue de sa teneur 

 en glucose, independant du 

 miheu interieur de la mere. 

 Tout se passe done comme si 

 le foetus reglait sa propre gly- 

 cemie." 



As we have already seen, 

 Aron established the fact that 

 the appearance of the islets of 

 Langerhans in the foetal pan- 

 creas and the installation of the 

 glycogenic function of the liver '^* ^ ^' 



are synchronous events in the life of the embryo. Aron now found, 

 working with dogs and cats, that, although the islets of Langerhans 

 appear in the former case not till after the 7th week of gestation and 

 in the latter case well before this time, their appearance was always 

 marked by a greater independence of the foetal circulation. Before 

 their appearance, the removal of the maternal pancreas led to an 

 elevation of the maternal blood sugar which was reflected very closely 

 by a rise in the foetal blood sugar, but afterwards, this correspondence 

 was not nearly so marked. Thus at the 6th week in the dog, after 

 removal of the maternal pancreas, the blood sugar was 360 mgm. 

 per cent, in the mother and 340 mgm. per cent, in the foetus, but 

 at the beginning of the 7th week, when a similar experiment was 

 tried, the values were respectively 274 mgm. per cent, and only 

 1 75 mgm. per cent. Although the protection of the embryonic in- 

 sulin was not complete, yet the embryo was clearly defending itself 



