Guinea pig 130. Black and brown male. Weight, 800 grams. Diet, oats and hay.

June 6: 2.30 p. m., 12 cc of 2 per cent caffein (0.3 gram per kilo) administered by mouth; 3 p. m., reflexes increased; 5 p. m., increase of reflexes greater than at 3 p. m.

June 7: 9 a. m., found dead; only a few cubic centimeters of urine passed since 4 p. m. Autopsy: Heart and blood vessels injected; lungs congested; small intestines congested slightly.

Guinea pig 181. White and yellow male. Weight, 860 grams. Diet, oats and hay.

June 6: 2.40 p. m., 12 cc 2 per cent caffein administered by mouth; 3 p. m., reflexes increased; 5 p. m., reflexes still more marked.

June 7: 9 a. m., found dead, pig passed about 5 cc urine since 4 p. m. of previous day. Autopsy: Same as in No. 130.

Guinea pig 136. White and black male. Weight, 1,000 grams. Diet, oats and hay.

June 9: 4 p. m., 7.5 cc 2 per cent caffein solution injected subcutaneously into the back; 4.50 p. m., reflexes increased.

June 10: 9.30 a. m., more sensitive than normal guinea pigs, but reflexes not quite so marked as at 5 p. m. previous day, about 15 cc urine passed since caffein was injected, reduction of Fehling's solution considerable, no albumin.

June 13: Alive and in good condition. Appetite good. (Note.—Parallel test with urine from two guinea pigs which did not receive caffein failed to show reduction of Fehling's solution.)