The more frequently it has become necessary to obtain sufficient blood from infants for various diagnostic purposes in recent years, the more evident is the fact that the various methods of obtaining it are unsatisfactory. The method of scarification gives tissue juice in addition to blood and is not applicable for bacteriologic work on account of the frequent contaminations. The method of obtaining blood from the veins of the scalp, from the jugular or other veins, is very difficult and open to frequent failures. This is especially true in some toxic conditions in which even the external jugular is not to be seen or palpated.
From the anatomic point of view there is one place that is far superior to any other for the purpose of obtaining blood, namely, the longitudinal sinus in the area of the anterior fontanel. Inasmuch as the sinus grows gradually larger toward the back of