Bacteriophage lysis is inhibited by blood, serum, leukocytes, bile and tissue débris. Many bacteriologists have concluded, therefore, that bacteriophage would necessarily be an ineffective therapeutic agent in most regions of the animal body. This conclusion apparently is premature, as shown by recent demonstrations of the multiplication of bacterophage in chick embryos1 and in infected brain tissues of white mice.2 In both cases the proliferation is associated with positive therapeutic effects.
The chorioallantoic membrane of the developing chick embryo is a useful medium for the cultivation of many viruses and bacteria. Weil and Volentine,3 for example, showed that Bacterium shigae will proliferate on this membrane and will usually cause death of the embryo in from two to four days; increase in the bacterial count is demonstrable as early as five hours after the bacillus is placed on the membrane. At this five hour period the Rakietens1 introduced