Massie, Skin of the Tadpole. 1 1 



Fig. i. Illustrating a nerve terminus in the skin at about the middle of 

 this period. The principal fibre shown isjmedullated up to the dense middle 

 layer of the corium, where it loses its sheath and then follows a sinuous course 

 over the surface of the cells of the Malphigian layer. The ectal and ental cells 

 of this layer are well differentiated. 



Fig. 2. Section through the skin of an older specimen. The horny layer is 

 now two cells thick throughout, the ectal series of Malphigian cells is rapidly 

 subdividing and the intra-cellular skeins have in several cases assumed stellate 

 forms. A gland is shown in process of formation at the right and at the left a 

 nerve fibre passes up through the corium and branches over the surface of the 

 epidermal cells. 



Fig. j. Section through the skin at a considerably younger stage. A blood- 

 vessel is seen under the Malphigian layer. Most of the corium has been torn 

 away. 



Fig. 4. Section from a little older specimen than the last, showing a 

 slightly different typical form of intra-cellular skein ; h, horny layer, beginning 

 to become two cells thick, ec, ectal series of Malphigian layer, en, ental series. 



Fig. j\ Section of about the same stage as the last, showing the three 

 layers of the corium. Kelow the lowest layer a nerve-bundle is seen, which 

 sends a fibre up to the epidermis, where it branches freely over the cells of the 

 Malphigian layer. 



Fig. 6. Section showing a gland at a slightly more advanced stage than 

 the one illustrated in Fig. 2. 



