LOCAL SPECIFIC THEEUPY OF INFECTIONS 111 
lymph spaces and the several serons cavities. Plie lymph 
surrounding the spermatic eord may approach in protein con¬ 
tent that of the blood ; while the lymph transndate in the pleura 
may show in a thousand parts 20 of protein, in the perito¬ 
neum 11, and in the cerebrospinal membranes 6. Since a 
close relationship exists between the protein and antibody 
content of the several lymphalic lluids, it follows that the 
Chemical composition of the lymph may well become a deci- 
ding factor in the issue of infection. Moreover, drugs which 
hâve been introdueed into the blood pass nlso unequally into 
the lymph. 
Parasites which therefore bave become localized in régions 
inaccessible or not readily accessible to the défensive or cura¬ 
tive principles contained within the blood are thus insured a 
potential advantage against the host ; and this advantage is 
strengthened by the circumstance that, as they multiply within 
a confined area to which the lymph bas not ready access, the 
immunity principles originally présent are exhausled. 
Still other factors play a part in determining lhe issue of 
infection. It is not sufficient that curative principles shall be 
possessed since it is also necessary that they be able to act 
upon the microbic causes of disease in such a degree of concen¬ 
tration as to insure maximal effect. We already know that for 
trypanosomal, meningococcal and streptococcal infections, lhe 
liigher the concentration is of lhe specilic immune sera about 
the parasites, the greater the assurance of their destruction [2]. 
Moreover, variation and mutation occur among microorga- 
nisms which operate to détermine their susceptibilités to 
injnrious agencés, whether immunity bodies or drugs. Even 
phagocytons is affected by variations in virulence among 
bacteria [3]. This factor bas corne to be regarded as highly 
important in deciding the issue of infection. In how far it can 
be set aside by the more direct local attack upon disease 
remains still to be determined; but the oportunity which the 
method affords of uniting immune sera and curative drugs in 
their action upon the parasites offers in this respect manifest 
advantages. 
ït is désirable to recall that in the course of their curative 
action, spécifie drugs are assisted in the destruction of parasites 
