1882.] 89 [Hinckley. 



of eggs the leeches would insinuate themselves through and 

 through it till in one instance every egg was eaten. 



My observations for the season of 1880, with additional notes 

 of 1881 and 1882, continue thus : 



April 12. Tadpoles hatched and collected on upper surface of 

 jelly. They measure about eight millimetres in length, are soot- 

 colored, with a lighter abdomen. Mouth and eyes undeveloped. 

 There are two prominent holders, one on each side below and 

 back of the cavity which marks the mouth, by means of which 

 the tadpoles cling to whatever they touch. Two small projec- 

 tions, one on each side below the prominences which mark the 

 eyes, are the external gills in process of development. The nos- 

 tril pits are conspicuous, and near the extremity of the head. 



April 13. Gills partially developed. Tadpoles increasing in 

 length by development of the tail. Body shows the presence of 

 food in the intestines. 



April 14. External gills, which are fully developed, consist of 

 two branches on each side the head, with from four to six 

 processes in each. These gills are occasionally shaken. 

 Throughout their length the blood corpuscles may be seen mov- 

 ing by throbs. A membrane has developed from before the gills 

 and is gradually growing downwards over them. Eyes and 

 mouth developing ; the latter taking its place nearer the extremity 

 of the head. Holders losing prominence. Tadpoles occasionally 

 wriggle about, usually in a circle. The grasses and weed stalks 

 immediately at hand are black with their clinging forms. 



April 15. Noticed to-day a movement of the jaws of the 

 mouth. A golden dotting is seen on the eye. Gills growing 

 limp, and circulation decreasing as they are resorbed. Form 

 of tadpoles more rounded. 



April 16. Gills on right side resorbed. A few golden dots 

 have appeared on the body and along the sides of the head from 

 the mouth back under the eyes. A line of the same color is visi- 

 ble down the middle of the muzzle. 



April 17. Gills on left side nearly resorbed. Golden dotting 

 on body increasing. Mouth shows incipient papillae at edge of 

 border. Eyes more fully developed. 



April 18. Gills resorbed on left side, leaving a small, oblique, 

 cone-shaped tunnel with a rounded opening at the top. Looking 



