70 Weights of Human Viscera 
Forming as before a table of coefficients of variation, we have : 
TABLE C. 
Relative Variabilities of General Hospital Population of Hearts and Spleens 
at different Ages. 
Organ 
Coefficient of 
Variation 
Organ 
Coefficient of 
Variation 
Heart, 25—35 
Heart, 35 — 45 
Heart, 45—55 
32-79 
30-53 
32-42 
Spleen, 25—35 
Spleen, 35 — 45 
Spleen, 45 — 55 
50- 42 
51- 97 
50-24 
We can draw some important results from the above constants. 
(a) The heart in the general hospital population of adults increases far more 
rapidly with age than it does in the class of healthy hearts. On the other hand 
the weight of the spleen sensibly decreases. 
{h) The absolute variability of the heart increases 10 per cent., and the absolute 
variability of the spleen decreases 17 per cent, during the period considered. 
These are quite sensible changes. Thus, while the heart tends to grow larger and 
more variable, the spleen tends to grow smaller and less variable. 
(c) If we deal with relative variation as judged by the coefficient of variation, 
we see that the changes referred to under (a) and (b) almost balance each other. 
Or, the relative variabilities of both heart and spleen remain sensible constants 
with age and equal to the values found for the general hospital population of adults 
of all ages in Table A, p. 66. This is further evidence of the real value of the 
coefficient of variation as a biometric measure of variability. 
{d) The correlation between heart and spleen steadily increases with age. In 
the first period it is comparatively small, in the second period it has much the 
same value as in the general hospital population of adults (see p. 65), and in the 
third period it approaches the value found for healthy adults. 
These results are quite reasonable. As death below the age of 35 is generally 
abnormal*', we should expect to find that the coefficient of correlation was low. 
Over the age of 45 years there is a slow deterioration of all organs. There is no 
evidence to show that this degeneration is much more acute in any one of the 
organs we are considering than in any other. Therefore, although the absolute 
weights will differ from the normal, the correlation may be the same, and this we 
see that it actually is. 
* By "abnormal" is meant here a death due to disease; the result of an accident would be from 
this point of view a normal death, as probably leaving the viscera "healthy" under post-mortem 
record. 
