64 Manual of Veterinary Microbiology. 



result of a diminution in the loss of heat through 

 constriction of the peripheral capillaries. Rise of 

 temperature therefore does not, in all cases, imply 

 increased production of heat. 



Several microbic substances are known to possess 

 this pyretogenic or fever-begetting property : those 

 derived from the bacillus of blue pus, from Freid- 

 lander's microbe, etc. 



Further, the soluble products of the anatomical 

 elements themselves produce similar effects. Ac- 

 cording to Gangolphe and Courmont, necrobiosis of 

 the tissues develops pyretogenic substances inde- 

 pendent of all microbic intervention. These authors 

 have observed that histournage is followed by fever 

 when the testicular products are able to penetrate 

 into the blood, whilst fever is absent if the precaution 

 be taken to put a ligature completely around the scro- 

 tum so as to prevent all absorption. It is not impos- 

 sible that the super-activity of the phagocytes, strug- 

 gling against microbic invasion, becomes also the 

 starting point of the production of pyretogenetic 

 substances, a hypothesis which certain facts seem to 

 indicate. We know, moreover, that extracts of flesh 

 and of the spleen possess similar properties, which 

 thus appear to belong to a certain number of the 

 residues of normal disassimilation. 



Some soluble substances of microbic origin excite 

 the phenomenon of hypothermia, lowering the tem- 

 perature of the body ; this property is possessed by 

 the soluble products of the comma bacillus of cholera, 

 the septic vibrio, and the staphylococcus aureus. 



The nervous system is especially sensitive to the 

 action of these products of microbic origin, in the 



