_Rabbit 181. Belgian hare. Weight, 1,230 grams._ (Was experimented on some time previously.) February 16: 10.55 a. m., 8 cc 2 per cent caffein injected into the lumbar muscles; (0.130 gram per kilo); 12 noon, no symptoms; 2 p. m., no symptoms; 3 p. m., put on the floor, walked about 10 feet and was exhausted, posterior extremities paralyzed; 4 p. m., found dead. SERIES C. In the fall of the same year additional experiments were carried out with doses ranging from 100 to 200 milligrams of caffein per kilo, which were injected into the lumbar muscles. The results are given in the following abbreviated protocols: _Rabbit 425. Belgian hare. Weight 1,520 grams._ September 27: 10.30 a. m., 7.5 cc 2 per cent caffein injected into the lumbar muscles; 2 p. m., reflexes increased. September 28: Rabbit normal. October 5: Weight, 1,620 grams; 2.50 p. m., 10 cc 2 per cent caffein injected into lumbar muscles; 3.05 p. m., reflexes increased. October 13: Weight, 1,520 grams; 10.30 a. m., 10 cc 2 per cent caffein (131 mg per kilo) injected; 11 a. m., no symptoms; 11.30 a. m., reflexes much increased. October 14: Alive, no symptoms. _Rabbit 426. Belgian hare, female. Weight, 1,425 grams._ September 27: 7 cc 2 per cent caffein injected into the lumbar muscles at 10.30 a. m.; 2 p. m., reflexes increased. September 28: Rabbit normal. October 5: Weight, 1,425 grams; 2.55 p. m., 9 cc 2 per cent caffein injected into lumbar muscles; 3.05 p. m., reflexes increased. October 13: Weight, 1,405 grams; 10.30 a. m., 10 cc 2 per cent caffein (142 mg per kilo) injected; 11 a. m., no symptoms; 11.30 a. m., reflexes increased. October 14: Rabbit alive, no symptoms. _Rabbit 427. Belgian hare, female. Weight, 1,780 grams._ September 27: 9 cc 2 per cent caffein injected into the lumbar muscles; 2 p. m., reflexes increased. September 28: Rabbit normal. October 5: Weight, 1,850 grams; 3 p. m., 11.5 cc 2 per cent caffein injected into lumbar muscles; 3.10 p. m., reflexes increased. October 13: Weight, 1,830 grams; 10.40 a. m., 14 cc 2 per cent caffein (153 mg per kilo) injected into lumbar muscles; 11 a. m., no symptoms; 11.30 a. m., reflexes increased. October 14: Rabbit alive, no symptoms. _Rabbit 453. Belgian hare, male. Weight, 1,160 grams._ October 12: 3.45 p. m., 11.5 cc 2 per cent caffein in aqueous solution injected into lumbar muscles; 4.15 p. m., reflexes increased; 4.30 p. m., paralyzed. October 13: 9 a. m., found dead. _Autopsy_: Gastric mucosa hemorrhagic; liver darkened; other organs normal. _Rabbit 455. Belgian hare, gray, female. Weight, 1,185 grams._ October 12: 3.30 p. m., 11.5 cc 2 per cent caffein injected into the lumbar muscles; 4 p. m., reflexes increased. October 13: Rabbit weighed 1,070 grams, no symptom of caffein poisoning, reflexes normal; 10.30 a. m., 10 cc 2 per cent caffein injected into the lumbar muscles; 11.30 a. m., jumped off the table, had attack of convulsions and died. _Autopsy_: Findings same as in No. 453.