M. Greenwood 
69 
Average weight of Heart at 20 years is 10'48 ozs. 
30 „ „ 10-80 „ 
40 „ „ 1112 „ 
50 „ „ 11-45 „ 
60 „ „ 11-77 „ * 
As far as I am aware, the correlation between age and weight of body in adult 
males is unknown. We should a priori expect it to be greater than the above, but 
it is always dangerous to judge without actual data. The correlation between 
stature and age is known, and is actually negative ; the stature of the adult male 
diminishing by about i inch for ten years after his prime at 28 yearsf. We thus 
conclude that while the stature decreases by \ unit, the heart increases by ^ unit 
per ten years. 
When we remember that the healthy heart is on the average much smaller 
than the heart in disease, and that sickness on the average increases continuously 
with agej, we shall probably lay less emphasis on the general a priori idea that 
the weight of the adult heart increases very sensibly with age alone. 
For my second inquiry I had unfortunately not sufficient material to divide 
my healthy hearts into three age groups and thus determine the influence of age 
on variability and correlation. I should have got less than 180 cases for each 
table. I was thus reluctantly compelled to deal with hearts in the general 
hospital population. 
I divided them into three gi'oups, ages 25 — 35, 35 — 45, and 45 — 55. The 
following results were reached : 
Age Influence on Hearts and Spleens of General Hospital Poptdation. 
TABLE VIII. Hearts and Spleens. Ages 25—35. Number 358. 
Mean Heart 11-91 ozs. Standard Deviation 3-997 ozs. 
Mean Spleen 7-45 ozs. Standard Deviation 3-758 ozs. 
Correlation of Heart and Spleen = "0785 ± -0384. 
TABLE IX. Hearts and Spleens. Ages 35—45. Number 536. 
Mean Heart 13-16 ozs. Standard Deviation 4-018 ozs. 
Mean Spleen 6-60 ozs. Standard Deviation 3-428 ozs. 
Correlation of Heart and Spleen = -1817 ±-0282. 
TABLE X. Hearts and Spleens. Ages 45—55. Number 403. 
Mean Heart 13-65 ozs. Standard Deviation 4-425 ozs. 
Mean Sj^leen 6-21 ozs. Standard Deviation 3-120 ozs. 
Correlation of Heart and Spleen = -2518 ±'0315. 
* Clendinning gives, Ages 15—29, 8i ozs.; 30—50, 9^ ozs.; 50—60, 10| ozs. Med. Chirurg. Trans. 
1838. See also Peacock and Keid, op. cit. 
t Biometrika, Vol. i. pp. 46-9. 
t Biometrika, Vol. ii. pp. 260 et seq. 
