170 THE STRUCTURE OF MAN 
in the frequency of its occurrence in advanced age, as will be 
seen from the following table :— 
From the 1st—10th year occlusion observed in 4 per cent. 
»  10th—20th Ki i 11 ae 
»  20th—30th if ! 17 
| 30th==40¢th is - 25) ee 
»  40th—50th o 27 We 
»  50th—60th ‘ ¥ 36 ee 
, 60th 70th ee ‘, 5o° ae 
~) f0th—=s0th . - 58 aw 
It follows from the foregoing table that in more than 50 per 
cent of people over sixty years of age there is degeneration of the 
vermiform process. In new-born children, on the other hand, 
this phenomenon has never been observed, and the youngest 
child in whom it has been found commencing was five years old. 
Total occlusion is also similarly connected with age, though not 
in nearly so marked a manner as partial closure. It has never 
been observed before the thirtieth year; and while it was not 
found once in individuals between fifty and sixty, it was most 
frequent in those whose ages ranged from sixty to seventy. Among 
these, nine out of the twenty-one cases recorded showed complete 
occlusion ; and since besides them there were seven just on the 
point of closure, we may conclude that more than 50 per cent 
were thus affected. 
A relation has further been proved to exist between the 
length of the appendix and its degeneration. The longest 
appendices (21 to 15 cm. long) kept their lumen throughout ; 
in those 14 and 13 cm. long, commencing obliteration of the 
lumen was observed in four cases, and in those 12 and 11 ecm. 
long it was not found. From this point, however, occlusion 
again increased as the length decreased. If we leave out of 
account individuals under five years of age, in whom occlusion 
has not been observed, we find that it occurs as under, viz.— 
Where the length of the appendix is 20 cm. in 34 per cent. 
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Although this connection between length and frequency of 
occlusion is, as the table shows, somewhat irregular, we may at 
