170 
Journal of Agricultural Research 
Vol. IX, No. 6 
B.—EFFECTS ON THE LEUCOCYTES 
10,000). Zuntz and Schumberg (5, 7) found an increase of 43 per cent 
in the number of leucocytes in soldiers, following marches. Hawk, in 
his college athletes, found an increase of from 21 to 104.4 P er cent, with 
an average of 57.0 per cent. Schneider and Havens (7) found an in¬ 
crease which varied from 13.8 to 130.2 per cent and returned to normal 
in a very short time (30 to 45 minutes). 
In animals Cohnstein and Zuntz (5) found a leucocytosis in rabbits,, 
following muscular exercise. In pigs we have found, on an average, 
an increase of 18.88 percent. This increase, however, was not uniform; 
and in some cases it was lower after exercise than before (for explanation, 
see*“Discussion of results” and “Control experiments'’). 
I.—CHANGES IN DIFFERENTIAL, COUNTS 
Tarrabee (3, 5) not only found a leucocytosis in the blood of the long¬ 
distance runners which he examined but he also found the polymorphs 
to be increased. The eosinophiles were absent in three cases and much 
reduced in the fourth. The number of transitionals was increased. 
Zuntz and Schumberg (5, 7) obtained an increase of polymorphs from 
6 to 11 per cent, and a decrease in the lymphocytes from 3 to 17 per cent. 
Schneider and Havens (7) found an increase of 9 to 45 per cent in poly¬ 
morphs, and a decrease of 14 to 55 per cent in the lymphocytes. They 
found no definite change in the proportions of the various kinds of 
leucocytes at the close of the exertion, but slowly thereafter and through¬ 
out a period of from 1 to 2 hours the polymorphs increased and the 
lymphocyte index (including lymphocytes, mononuclears, and tran¬ 
sitionals) decreased. They found that the normal proportions returned 
after about 2 to 4 hours. They state that the changes in the differential 
count continued long after the normal number of leucocytes had been 
returned. Burrows (7), on the other hand, in a study of a single case, 
. found that exercise decreased the polymorphs and increased the 
lymphocytes. 
In pigs we have found a condition similar to that reported by Larrabee, 
Zuntz, and Schumberg and Schneider and Havens for man, except that 
the normal proportions did not return until after a much longer period. 
Differential counts of the leucocytes indicate a slow destruction of the 
lymphocytes of the blood following muscular exercise and an increase 
of the polymorphs. 
In 15 experiments in which the examinations were made shortly after 
the exercise there was an average decrease of 12.61 per cent of lympho¬ 
cytes, an average increase of 15.13 per cent of polymorphs, an average 
decrease of 2.34 per cent of eosinophiles, a very slight increase in the 
mononuclears, and a slight decrease in the masts. 
