102 



Albert I. Lansing 



which distinguish them from the elastic elements found in 

 senile arteries. 



The senile elastic tissue of arteries manifests a weak 

 acidophilia whereas the opposite is true in senile elastosis. 

 When the elastic fibres of the latter lesion are stained with a 

 dye such as methylene blue or toluidine blue the fibres exhibit 



? 100 ' 



Fig. 4. Graphs sliowing the uptake of ^*C labelled glycine in 



normal rabbit aortic elastin and in aortic elastin of rabbits 



treated with elastase. 



a strong basophilia. No evidence of metachromasia has been 

 observed so far by us. Another striking difference between 

 ageing of arterial and dermal elastic tissue exists in the 

 calcium content of the two. As has already been indicated 

 the ageing of arterial elastic tissue may be measured in terms 

 of the amount of calcium it contains. Juvenile arterial elastic 

 tissue is free of calcium; with age it progressively takes up 

 calcium, as much as 18 per cent of the dry weight of the 



