October 4: 5 cc 2 per cent caffein (0.2 gram per kilo) injected subcutaneously in the back at 3 p. m.; 5 p. m., no symptoms. October 5: 9 a. m., condition good. _Guinea pig 60. White and gray female. Weight, 320 grams. Diet, oats._ October 3: 2.25 p. m., 3.5 cc 2 per cent caffein (0.219 gram per kilo) injected subcutaneously in the back; 3.40 p. m., convulsion with recovery; 3.50 p. m., frequent spasms with paralysis, especially of anterior extremities; 5.30 p. m., tetanus when removed from cage and put on floor. October 4: 8.50 a. m., found dead. _Autopsy_: Congestion of small intestines, lungs, liver. _Guinea pig 57. White and gray female. Weight, 350 grams. Diet, oats._ October 3: 2.15 p. m., 3.5 cc 2 per cent caffein injected subcutaneously in the back (0.2 gram per kilo); 3.40 p. m., convulsions with recovery; 5.30 p. m., no marked symptoms. October 4: 8.50 a. m., alive, active. October 6: Found dead at 9 a. m. _Autopsy_: Congestion of lungs and liver; kidneys petechiated; severe gastro-enteritis. _Guinea pig 68. Yellow male. Weight, 785 grams. Diet, oats._ October 6: 11.35 a. m., 7.8 cc 2 per cent caffein (0.2 gram per kilo) injected subcutaneously; 12 noon, reflexes increased markedly; 4.20 p. m., reflexes the same as at 12 noon. October 7: 9 a. m., dead. _Autopsy_: Lungs congested; liver congested and fatty; spleen congested, kidney showed hemorrhagic spots; gastric mucosa necrotic; small portion of small intestine inflamed. _Guinea pig 69. White male. Weight, 585 grams. Diet, oats._ October 6: 11.40 a. m., 5.8 cc 2 per cent caffein injected subcutaneously; 12 noon, reflexes increased, but not as much as in No. 68; 4.20 p. m., guinea pig hypersensitive, reflexes increased more than at 12 noon. October 7: 9 a. m., alive. October 15: 9 a. m., found dead. _Guinea pig 61. Brown and black female. Weight, 330 grams. Diet, oats._ October 3: 4 p. m., 4 cc 2 per cent caffein (240 mg per kilo) injected subcutaneously; 5.30 p. m., reflexes increased; runs, but drags posterior extremities. October 4: 8.50 a. m., found dead. _Guinea pig 62. White, yellow, and black female. Weight, 335 grams. Diet, oats._ October 3: 4.05 p. m., 4 cc 2 per cent caffein (238 mg per kilo) injected subcutaneously in the back; 5 p. m., convulsions; 5.20 p. m., convulsions, alternating with paralysis of anterior and posterior extremities. October 4: 8.50 a. m., found dead. _Guinea pig 70. White and brown male. Weight, 545 grams. Diet, oats._ October 7: 3 p. m., 6.5 cc 2 per cent caffein (238 mg per kilo) aqueous solution injected subcutaneously; 3.50 p. m., reflexes increased. October 9: 9 a. m., found dead. _Guinea pig 71. Brown and white male. Weight, 540 grams. Diet, oats._ October 7: 3 p. m., 6.5 cc 2 per cent caffein solution (0.24 gram per kilo) injected subcutaneously; 3.45 p. m., reflexes increased, tetanus. October 9: 9 a. m., found dead. _Guinea pig 72. Brown and white male. Weight, 560 grams. Diet, oats._