DEVELOPMENT OF THE COMMON FROG. 101 



peared ; and their place was marked by two very small 

 scars, blackened by closely set spots of black pigment. 

 The skin of the whole body was dotted over with very 

 small black spots ; and here and there were gold spangles, 

 not so numerous nor so regularly placed on the ventral 

 side as on the back. There was a distinct slightly indented 

 line, marking the union of the opercular fold with the skin 

 of the abdomen ; and on approaching the left side it turned 

 backwards and formed the right border of a funnel, at the 

 end of which was the opening of the gill-chamber. The 

 rudiments of the hind limbs were no larger than they were 

 ten days ago. 



A few days since, some of the confervse growing on the 

 sides of the pond was scraped off and put into the basin 

 with the tadpoles to serve for food. 



32. Three life-size drawings of tadpoles were made : 

 two of these show different sizes among tadpoles of the 

 same age; the third is a side view, showing the protuberant 

 abdomen. 



The tadpoles in the basin still attach themselves to the 

 sides, most frequently near the surface of the water. They 

 seem to have some difficulty in doing so, and they are not 

 very secure when attached ; but they pass perhaps half 

 their time thus stationary. Excepting in a few backward 

 tadpoles, the suckers have disappeared, and it would seem 

 that they now hold by their mouths when attached. They 

 grow well and are very lively ; but not more than three or 

 four at a time are to be seen eating the confervse, and they 

 not show any remarkable eagerness for food. 



32 (2) . A drawing was made of the upper surface of a 

 tadpole seen by transmitted light. The head and body 

 were bordered by a transparent fold of the skin. The 

 opening out of the gill-chamber on the left side was very 

 plainly seen. The vent was open, a quantity of fsecal 



