^ 



'-y^ 



'.. Vv 



ym 



V .'■- 



'''^^^m>'^^0^- 



^mt' -. 



a 



Plate II. Vesicles in the skin of the frog, produced by different agents, 

 a is a normal skin. In h the prickle cells adhere firmly to oneanother, 

 and to the dermis; the cornified layer splits away from the prickle cells. 



