58 Dr. F. W. Pavy on the Production of Glycosuria. [Nov. 25, 



to pass into sugar, and thence determine a saccharine condition of these 

 liquids ? At a later period of foetal life the liver becomes charged with 

 amyloid substance, and sugar is no longer discoverable in the liquids 

 named. But now the chylo-poietic viscera have attained considerable 

 development, and would send venous blood through the portal vein to the 

 liver. It is a specially notable fact, in relation to this point, that the 

 liver and chylo-poietic viscera do not correspond in their state of develop- 

 ment at different periods of foetal life. If they did there would be no 

 alteration in the relative supply of portal and umbilical blood to the 

 former as time advanced. The liver, on the contrary, at an early stage is 

 vastly out of proportion in size to even every other part of the organism. 

 In the human foetus, at the third or fourth week of embryonic life, it 

 is said to constitute one half of the weight of the whole body*. At the 

 commencement, then, the chief supply of blood to the liver must be from 

 the umbilical vein. Subsequently, as the developmental relation becomes 

 altered and the chylo-poietic viscera attain significant dimensions, the 

 supply of venous blood must correspondingly increase. This may be ac- 

 cepted as a necessary deduction without reference to the precise anato- 

 mical disposal of the umbilical vein in relation to the liver. Under the 

 view propounded, what before stood as an incomprehensible phenomenon 

 becomes susceptible of rational explanation. 



While the presence of amyloid substance is confined, or almost en- 

 tirely confined, in the adult to the liver, it is known to have a somewhat 

 wide extent of distribution amongst foetal structures. Now in harmouy 

 with this the tissues of the foetus, unlike those of the adult, are supplied 

 with a mixture of venous and arterial blood. 



The lungs and muscles are found to represent two structures besides the 

 liver in which amyloid substance has been encountered in the adult; but 

 examination shows that when it happens to be here physiologically recogni- 

 zable it is only so to a comparatively inconsiderable extent, and this under 

 circumstances involving a reduced supply of arterial blood. For instance, 

 it is especially in muscles that have been kept in a state of rest, and in those 

 of the hybernating animal during hybernation, that the substance has 

 been noticed to be discoverable, and it has been observed to disappear 

 under a state of activity. The lung- tissue during hybernation has been 

 found to yield it, but fails to do so when activity is resumed. 



It is an interesting and apparently a significant fact that amyloid sub- 

 stance is present to a notable extent in the solidified lung of pneumonia. 

 I have myself obtained it in considerable quantity from lung-tissue in 

 this state. Now it happens that we have here a condition, as regards 

 the relation to blood-supply, which closely resembles that of the liver, 

 for the tissue being solidified and impervious to air will not admit of oxy- 

 genation going on, and the blood which reaches it through the pulmonary 

 artery, like the main supply to the liver, is of a venous character. 

 * Quain's 'Anatomy/ 7th ed. p. 879. 



