1904-5.] Simultaneous Removal of Thymus and Spleen. 389 
The Effect of Simultaneous Removal of Thymus and 
Spleen in young Guinea-pigs. By D. Noel Paton and 
Alexander Goodall. ( From the Laboratory of the Royal 
College of Physicians , Edinburgh.) 
(Read December 5, 1904.) 
We have already shown that removal of the spleen (1) or of the 
thymus (2) has very little effect on the animal economy. Since 
the spleen and thymus together comprise the largest amount of 
lymphoid tissue in the body of young animals, it would appear not 
improbable that although removal of either of these organs causes 
no marked disturbance, their simultaneous extirpation might be 
expected to give rise to some more manifest change. Friedleben 
(3) states that, while in his series of experiments no dog died of 
removal of the thymus, and that the removal of the spleen in 
young dogs does not influence the course of life, the simultaneous 
removal of the thymus and spleen causes a marked deterioration 
of blood formation, and leads to death. 
Since his experiments were made without aseptic precautions, 
and since his results may therefore have been due to sepsis, it 
appeared desirable to repeat these observations on young guinea- 
pigs, in which animals removal of the thymus and of the spleen 
separately has been found by us to cause no disturbance of 
importance. 
In the following series of observations D. Noel Paton is 
responsible for the operations, which were performed under full 
anaesthesia. The animals invariably recovered rapidly. There 
was never suppuration, or any evident discomfort to the animal. 
The observations on the blood were made by A. Goodall. 
Experiment I . — On 9th April two female guinea-pigs were 
brought under observation. A. weighed 200 grms and B. 160 grms. 
A. had thymus and spleen removed: — thymus ’3 grm., spleen 
T8 grm. 
