Florence R. Sabin 



187 



size of the primary ducts. The ease of injection in any direction shows 

 that there are no valves at this stage, though the flow of any injection 



Fig. 4. The lymphatic system in the skin of a pis -l-S em. lonj;. x 3. 



mass is irregular on account of tlie great variation in the size of the 

 channels. In making these injections it is essential to enter the needle 

 into the level wliich contains the lymphatics. As will be shown later. 



