Hall. — Mesonephroa in Amphibia. 



PLATE 7. 



All figures are of cross-sections. 



Fig. 77. (See explanation of Plate 6.) 



Fig. 78. Hyla. A cross-section immediately posterior to the common nephrostome 

 and cutting the third (second -f third ?) Miillerian evagination. X 308. 



Fig. 79. Rana. A cross-section through the folded portion of the epithelial band 

 of the right side of the body of a larva 35 mm. long. X 188. 



Fig. 80. Rana. A section behind that of Figure 79, showing the coalescence of 

 the edges of the folded epithelial band. X 188. 



Figs. 81-83. Hi/la. Three sections through the right pronephros of a young larva. 

 The first (Fig. 81) passes through the first nephrostome, cutting the 

 fundament of the first Miillerian evagination ; the second (Fig. 82) 

 passes through the common nephrostome, cutting the second (second 

 + third?) evagination; the third (Fig. 83) cuts the epitlielial band 

 midway between the first and the common nephrostome. X 150. 



Fig. 84. Hyla. A section of the second (second + third ? ) evagination at an 

 earlier stage tiian that of Figure 78. X 308. 



Figs. 85, 86. Ht/la. Two sections from the left side of an abnormal larva. That 

 of Figure 85 passes between the second and third nephrostomes (which 

 have not fused to form a common nephrostome) and cuts the func'ament 

 of the second Miillerian evagination. That of Figure 86 passes behind 

 the third nephrostome and cuts the third evagination. X 308. 



