In April, 1909, Herrick and Janeway1 reported the finding of trichinellæ in the blood taken from the arm veins of a patient suffering from trichinosis. At the first trial four embryos were found in 10 c.c. of blood : a subsequent specimen of 1.5 c.c. from the same patient showed two trichinellæ, which were found without protracted search. An excellent Trichinella found in blood taken from an ordinary ear puncture. photomicrograph is reproduced in their article. Attempts to find embryos in blood taken from the veins of three other individuals of the same family with clinical trichinosis were unsuccessful.
In May, 1910, Mercur and Barach2 reported the finding of two trichina embryos in 10 c.c. of blood taken from the median cephalic vein, following the method of Staübli.
Herrick and Janeway's cases occurred in March, 1909; Mercur and Barach's in January, 1910.