it is very unlikely that when the immune serum is injected intravenously the antibodies reach the brain tissue by way of the cerebrospinal fluid , for ( 1 ) the antibody titer of the cerebrospinal fluid is lower than that of the brain extract , and ( 2 ) antibodies penetrate faster into the tissue of the brain than into the cerebrospinal fluid .
C0005889
fluid
C0003241
antibodies