108 DR. THOMAS ALCOCK ON THE 



Plate XV. 



6 1. A drawing of the ventral surface of a tadpole was 

 made, of the natural size. 



6 1 (2) . It was next turned on its right side and a slightly 

 enlarged drawing of the left side was made, showing the 

 opening into the gill-chambers. 



61 (3). The skin was then cut away from the abdomen, 

 and a drawing was made, natural size, showing a front 

 view of the helix-like coil of intestine undisturbed. This 

 view represents only a small part of the intestine, the coils 

 of which are several layers deep. 



The tadpoles in the pond, which were unusually large, 

 were a wonderful sight ; they were in dense crow 7 ds feeding 

 on the confervse. 



62. A slightly enlarged drawing of the left side of a 

 tadpole, in which the gill, fore limb, and coils of intestine 

 were exposed, was made. 



62 (2). The intestine was then pulled out and a drawing 

 made of the animal, natural size, with the intestine partly 

 uncoiled. 



63. A drawing was made of the right fore limb and gill 

 of a tadpole under the microscope with a two-inch object- 

 glass. The gill had an unusual appearance, a considerable 

 part of it consisting of a smooth white substance. 



Plate XVI. 



64. Two outline drawings of a tadpole, natural size, 

 were made — one a dorsal view, the other the left side ; both 

 showed the opening of the gill-chambers. 



66. A drawing was made of the left fore limb, left gill, 

 and heart of a tadpole under the microscope with the two- 

 inch object-glass. 



The tadpoles have now eaten all the confervas from the 



