_Rabbit 309. Belgian hare, female. Weight, 1,500 grams. Diet, oats._ March 2: 2.05 p. m., 2 per cent caffein solution (0.2 gram per kilo) injected into peritoneal cavity; 2.25 p. m., found dead, no urine found in bladder. _Rabbit 307. Belgian hare, female. Weight, 1,320 grams. Diet, oats._ March 2: 12 noon, urine obtained from bladder, clear amber colored, no albumin, no reduction; 12.06 p. m., 10 cc of 2 per cent caffein (0.151 gram per kilo) injected into peritoneal cavity; 1.30 p. m., rabbit placed on floor, runs around but anterior and posterior extremities soon extended, in tonic condition; 2.25 p. m., reflexes increased, paralysis of extremities, dyspnoea; 4.50 p. m., about 100 cc urine collected, no albumin, reduction of Fehling's solution moderate. March 3: 9.30 a. m., posterior extremities extended and rigid, anterior extremities paralyzed, respiration less frequent and deeper than normal. Rabbit died at 11.50 a. m.; urine collected since 4.50 p. m. previous day gave very heavy reduction of Fehling's solution. _Autopsy_: Animal in good condition; in the left axillary region was observed a hemorrhage into the subcutaneous and muscular tissue of that region. The ventral portion of the large colon, in contact with the ventral abdominal wall, showed a hemorrhagic area about one-half inch in length, such as might be produced by a puncture or bruise of the colon through the abdominal wall. A small portion of the small intestine adjacent to the colon was affected in a similar manner. All internal organs were apparently normal. _Rabbit 308. Belgian hare, female. Weight, 1,350 grams. Diet, oats._ March 2: 11.45 a. m., urine obtained from bladder, no albumen, no reduction; 11.50 a. m., 10 cc 2 per cent caffein (0.15 gram per kilo) injected into peritoneal cavity; 1.30 p. m., not very active, no abnormal symptoms otherwise; 3.30 p. m., rabbit looked depressed, made very little attempt to move about, remained in one position most of the time when placed on floor; 4.30 p. m., 180 cc urine collected, no albumen, reduction of Fehling's solution moderate. March 3: 9.30 a. m., rabbit looks normal, is able to walk but is easily fatigued when made to walk about or when placed on his side, followed by paralysis of anterior extremities, posterior extremities apparently normal, about 90 cc of urine collected at noon was free from albumen, did not reduce Fehling's solution. March 4: 11 a. m., lying on his side in cage, anterior extremities limp, posterior extremities extended and rigid, is in dying condition. March 5: 9 a. m., found dead. _Autopsy_: Liver engorged; spleen congested, but not enlarged; kidneys, some congestion in cortex; stomach filled, mucosa thickened and easily pulled off; petechial hemorrhages on serosa of colon. SERIES C. The experiments of this series were made to determine the minimum toxic dose. _Rabbit 295. Belgian hare, female. Weight, 1,205 grams. Diet, carrots._