Leucocytes from the Blood after Injection of Peptone. 297 



scope (Zeiss' 2 millimetres apochromatic, oil immersion, and 8 

 eye-piece) were counted in each section, several of which were 

 mounted from each organ, and, as will be seen, with very striking 

 uniformity of results. 



I shall now proceed to describe the results obtained in each experi- 

 ment. 



No. 1. Control Experiment. Rabbit, weight 2 kilos. The blood 

 irom an ear-vein was found to contain 6500 leucocytes per cubic 

 millimetre per cent, eosinophilous, 34 per cent, polynuclear, 20 per 

 cent, myelocyfces, 46 per cent, lymphocytes of which 2210 were thus 

 polynuclear. The animal was now killed by a blow on the head and 

 the organs at once removed. Four sections of the spleen were found 

 Jo contain 54, 47, 55, and 54 polynuclear leucocytes respectively 

 (twenty fields of the microscope being counted in each specimen), the 

 lung, 39 and 32, and the liver, 7, 6, and 7. 



It will be seen from the above enumerations that a remarkable 

 uniformity was found to exist in the distribution of the polynuclear 

 leucocytes in different sections of the same organ. This, I may here 

 mention, obtained throughout, not only in the control experiments, 

 but also after the injection of peptone. 



f No. 2. Control Experiment. Rabbit, 2 kilos. The blood from an 

 ear-vein was found to contain 3833 polynuclear leucocytes in each 

 cubic millimetre. Two sections of the spleen were counted and con- 

 tained, in 20 fields, 62 and 74 respectively ; the lung, 35 and 41 ; 

 iver, 5 and 6. 



No. 3. Control Experiment. To sho.w that the blood contained in the 

 ight and left ventricles does not differ markedly from the blood 

 taken from an ear-vein in the number of leucocytes contained in the 

 cubic millimetre the following experiment was made : 



Rabbit, 2 kilos. The blood from an ear-vein was found to contain 

 8500 leucocytes in each cubic millimetre. After an hour the*rabbit 

 was killed by a blow on the head, and the heart ligatured and re- 

 moved as soon after death as possible. 



The blood of the right ventricle was found to contain 7200 leuco- 

 cytes per cubic millimetre ; that of the left, 7500. 



The following experiment shows the number of polynuclear leuco- 

 cytes found in sections of the organs of an ordinary normal rabbit 

 after the leucocytes have been greatly diminished in the circulating 

 blood by the injection of peptone. 



No. 4. Rabbit, 2 kilos. Blood from the right ear contained 4015 

 polynuclear leucocytes. Three and a half hours after the injection 

 into a vein of the left ear of 3'5 grams peptone, dissolved in 35 c.c. 

 water, blood from the right ear only contained 1100 of the same 

 variety. 



Sections of the spleen prepared and examined in the same way as 



