1 86 Handbook of Nature-Study 



4. Take some of the plants found growing under water in the pond 

 and plant them among the stones. 



5. Carry the pan thus prepared back to the schoolhouse and place it 

 where the sun will not shine directly upon it. 



6. Bring a pail of water from the pond and pour it very gently in at 

 one side of the pan, so as not to disarrange the plants; fill the pan nearly 

 to the brim. 



7 . After the mud has settled and the water is perfectly clear, remove 

 some of the tadpoles, which have hatched in the glass aquarium, and place 

 in the "pond." Not more than a dozen should be put in a pan of this 

 size, since the amount of food and microscopic plants which are on the 

 stones in the mud, will afford food for only a few tadpoles. 



8. Every week add a little more mud from the bottom of the pond or 

 another stone covered with slime, which is probably some plant growth. 

 More water from the pond should be added to replace that evaporated. 



9. Care should be taken that the tadpole aquarium be kept where the 

 sun will not shine directly upon it for any length of time, because if the 

 water gets too warm the tadpoles will die. 



10. Remove the "skin" from one side of a tulip leaf, so as to expose 

 the pulp of the leaf, and give to the tadpoles every day or two. Bits of 

 hard-boiled egg should be given now and then. 



LESSON XLIV 



TOADS' EGGS AND TADPOLES 



Leading thought The toad's eggs are laid in strings of jelly in ponds. 

 The eggs hatch into tadpoles which are creatures of the water, breathing 

 by gills, and swimming with a long fin. The tadpoles gradually change to 

 toads, which are air breathing creatures, fitted for life on dry land. 



Method The eggs of toads may be found in almost any pond about the 

 first of May and may be scraped up from the bottom in a scoop-net. They 

 should be placed in the aquarium where the children can watch the stages 

 of development. Soon after they are hatched, a dozen or so should be 

 selected and placed in the tadpole aquarium and the others put back into 

 the stream. The children should observe the tadpoles every day, watch- 

 ing carefully all the changes of structure and habit which take place. If 

 properly fed, the tadpoles will be ready to leave the water in July, as tiny 

 toads. 



Observations i. Where were the toads' eggs found and on what 

 date ? Were they attached to anything in the water or were they floating 

 free? Are the eggs in long strings? Do you find any eggs laid in jelly- 

 like masses? If so, what are they? How can you tell the eggs of toads 

 from those of frogs? 



2. Is the jellylike substance in which the eggs are placed clear or 

 discolored? What is the shape and the size of the eggs? A little later 

 how do they look? Do the young tadpoles move about while they are 

 still in the jelly mass? 



3. Describe how the little tadpole works its way out from the jelly 

 covering. Can you distinguish then which is head and which is tail? 

 How does it act at first? Where and how does it rest? 



4. Can you see with the aid of a- lens the little fringes on each side of 

 the neck? What are these? Do these fringes disappear a little later? 



