Vaccine vesicle upon seventh day, showing beginning areola. Patient was suffering from scarlet 

 fever. Vesicle shows some irregularity in form. (Taken from Welch and Schamberg.) 



FIG. 14 



Vaccine vesicle upon ninth day, showing more pronounced areola. Same patbnt as Fig. 13. 

 (Taken from Welch and Schamberg.) 



