[26] 



Zbc 2)eveIop]iicnt of the ZCabpoIe* 



Bv J. W. Gatehouse, F.I.C. 

 Part 5. Plate IV. 



OUR previous observations on the life-history of the tadpole 

 of the frog led us to the point at which the little creature 

 was ready to eat with its mouth ; all previous growth having been 

 due to a gradual change of the undifferentiated cell contents, 

 combined with an absorption of water and food material from 

 the water, in a state of solution through the skin. 



The point at which we wish to arrive, is the nature of the 

 food eaten during the after-life history, extending for a period of a 

 little more than two months, the actual dates being from March 

 29th to June 12th. 



Referring back to Fig. i, PI. XX., in the last number of the 

 Journal of Microscopy, October, 1888, we see that the creature at 

 this period not only had no teeth, but that there appeared to be 

 no rudiments of any such organs, and therefore, that any nourish- 

 ment taken must have been of the softest and most delicate kind, 

 indeed far more of the nature of a solution as milk, than of a solid 

 as meat or green vegetable matter. It may here be well to men- 

 tion, that before the larv?e commenced to eat, they were separated 

 into two divisions, one set being placed in a tank with plenty of 

 vegetable matter, consisting of chara, alg^e, and duck-weed, with 

 no more animal matter than might be existing naturally on the 

 vegetation, whilst the other portion remained in the tank wherein 

 they had been from the beginning. This tank was kept absolutely 

 free from all vegetable matter during the whole period of the 

 experiments, the animals depending for their sustenance on 

 materials artificially supplied, the water being changed every 

 morning, with as little disturbance to the inmates as possible. 



This was effected by a kind of siphon of somewhat peculiar 

 form. The middle part of the instrument consisted of an india- 

 rubber tube, to which glass tubing was attached at either end. 

 Simple tubes answered nicely for a time, but as my pets increased 

 in size and were able to swim vigorously, they would rush to the 



