10 MODE OF PRODUCTION 



manner. Wherever active nutrition is going on, the 

 arteries of the part are observed to carry more blood. 

 This enlargement of the arteries will cause some 

 distension and relaxation of the capillaries, as they 

 cannot at once accommodate their calibre and con- 

 tractility to the greater quantity of blood forced into 

 them ; effusion of a more or less albuminous nature 

 will follow, and by its organisation the mass of the 

 particular organ will be increased. In childhood, 

 where growth and nutrition go on so rapidly, the 

 size of the arteries is relatively greater than at any 

 other period of life ; and wherever the formative 

 action proceeds with the greatest activity, there a 

 disposition of the vessels favourable to congestion, 

 and consequently to albuminous effusion, may be 

 observed to exist. 



In the impregnated uterus we have a still more 

 striking example of the connexion which exists 

 between a congested state of the vessels and the 

 process of growth or nutrition. The spermatic and 

 uterine arteries soon become enlarged and very 

 tortuous, the corresponding veins accompanying 

 them in their curves, albuminous effusion quickly 

 takes place from the vessels lining the uterine 

 cavity, it becomes organised, and the decidual mem- 

 branes are formed. In the meantime a similar state 

 of congestion has been produced in the capillaries of 

 its muscular and cellular coats, albumen is there 

 also effused, and when organised assumes the nature 

 of these textures, and thus the whole organ is in- 

 n-eased in size. The same arrangement of the vi^si-ls 

 so essential to the growth of the uterus and to the 



