340 SEQUENCE OF EVENTS IN GENERAL INFECTIONS 



other regions rich in lymphocytes, and we may probably corrobo- 

 rate this fact with the hyperplasia of the abdominal lymph glands, 

 Peyer's patches, and spleen which occurs in the disease, regarding 

 them as conservative, defensive phenomena, rather than the 

 pathological effects of the bacillus. 



After a latent period or negative phase of a few days (the dura- 

 tion being dependent on the severity of the infection), the antibodies 

 begin to make their appearance. At first put out only in small 

 quantities, they will be absorbed at once by the bacilli present, and 

 will not be demonstrable in the serum or plasma in a free state. 

 A race now ensues. On the one hand, the typhoid bacilli multiply 

 as rapidly as their environment will allow ; on the other, the 

 immune body and other defensive antibodies are being gradually 

 elaborated more and more rapidly. In a very severe infection 

 this latter process may perhaps make default altogether, and the 

 patient succumb during the negative phase. This has not been 

 demonstrated in the case of the bacteriolytic substances, but is 

 well known in the case of the agglutinins. In most cases, how- 

 ever, the increase of bacteria and of antibodies takes place at the 

 same time. After a time bacteriolysis occurs, but in small 

 amount, since but little immune body makes its appearance, and 

 that which is formed at first is probably utilized as opsonin. 

 Hence when solution of the bacteria and liberation of the toxins 

 does occur, it does so at first only to a small extent, and we may 

 regard it probable that the minute amount of endotoxin set free 

 does not add appreciably to the symptoms of intoxication already 

 present. Further, we have now the conditions under which 

 immunity to these toxins may be expected to develop : the setting 

 free of small but gradually increasing doses of endotoxin condi- 

 tions, in fact, closely similar to those obtaining in Macfadyen's 

 experiments. Probably, therefore, by the time that much bacterio- 

 lysis occurs the patient's tissues are more or less immunized. It 

 is, however, not unlikely that the rapid oscillations of temperature 

 characteristic of the latter stages of typhoid fever may be due in 

 part to this liberation of endotoxin. 



Some researches by Bail would appear to indicate that there is 

 a sort of automatic mechanism for the prevention of bacteriolysis 

 in the tissues. He found that no bacteriolysis took place when a 

 powerful serum was mixed with emulsions of cells from the liver, 

 spleen, etc, as well as with bacteria. The explanation is doubtless 

 that the complement is absorbed by these cells, as has been pointed 



