1917] VETERINARY MEDICINE. 381 



Twenty-five examinations of the blood of pigs weigliing In the neighborhood 

 of 100 lbs. showed the average number of erythrocytes per cubic millimeter 

 to be 6,215,000, and the average number of leucocytes, 18,000. The average 

 clotting time was found to be 57.6 seconds, specific gravity 1.062, and hemo- 

 globin percentage 79.4. The differential leucocyte count yielded lymphocytes 

 55.21, polymorphs 39.79, mononuclears 0.79, eosinophils 3.42, and mast cells 

 0.79 per cent. 



A detailed description of the various classes of leucocytes observed in the 

 investigation is submitted. The average differential counts in male and female 

 animals were found to be about the same, and also the counts by various 

 workers to be fairly uniform. The number of erythrocytes was found to vary 

 under different conditions, and to be higher in an animal in good condition 

 than in an animal of the .same age in poor condition. 



Effects of muscular exercise and the heat of the sun on the blood and 

 body temperature of normal pigs, C. C. Palmer {U. S. Dept. Agr., Jour. Agr. 

 Research, 9 (1917), No. 6, pp. 167-182, figs. 2). — This report of investigations at 

 the Minnesota Experiment Station has been summarized by the author as 

 follows : 



" Blood examinations in normal resting pigs, covering a period of 24 hours, 

 may be quite uniform ; but in some animals there is marked variation through- 

 out the period. . . . Results based on only one or a few experiments may lead 

 to wrong conclusions, owing to the variability in the blood of pigs." 



" Observations made upon a number of animals lead to the conclusion that 

 muscular exercise does not cause an increase of red corpuscles in the peripheral 

 circulation of the pig. . . . Evidence given by work with the pig tends to con- 

 firm the theory of perspiration being responsible for the increase in the number 

 of red corpuscles following muscular exercise in man. 



" Muscular exercise in the pig is usually followed by a leucocytosis. This 

 leucocytosis is probably the result of muscular exercise forcing leucocytes into 

 the general circulation from the tissues. Muscular exercise leads to marked 

 changes in the differential coimts. The mononuclear elements are decreased, 

 and the polymorphonuclear elements are increased. The height of the curve is 

 reached several hours after exercise, and the normal proportions do not return 

 for many hours. 



" Exposure to the sun causes similar changes in the differential curve. These 

 changes under both conditions are the result of increased rate of aging of the 

 leucocytes, the cells becoming older faster than young cells are being produced. 

 Muscular exercise and heat of the sun lead to a marked increase in body tem- 

 perature. Body temperature changes are more pronounced in fat pigs than lean 

 ones, but even in pigs weighing from 75 to 100 lbs. marked changes are likely 

 to occur. 



" Increased atmospheric temperature and increased percentage of humidity 

 lead to increased body temperature. 



" Blood examinations of pigs which are to be used for clinical records should 

 be taken from animals which have been confined in a small cool pen for at least 

 24 hours, and better, 48 hours. The animals must be kept absolutely quiet and 

 not worried. Feeding and watering should be regular. The daily blood exami- 

 nations should be made at the same time on each day. 



" Temperature records which are to be used for clinical records should be 

 taken from pigs kept in a cool, shady pen. The animals should not be exer- 

 cised or worried when the temperatures are taken. If the animals are chased 

 around the pen in endeavoring to obtain the temperature, the last temperatures 

 taken may show a marked rise. For tuberculin work where the temperatures 

 are used it would be best to keep them confined in a crate throughout the teat. 



