How many of you can tell me the difference between a frog-tadpole and a toad-tadpole? I don't mean when they are so small that it seems a kindness to call them tadpoles at all, but when they are quite a good size, with great fat heads and shiny little eyes and squiggly little tails. And how many of you can tell me the number of different kinds of tadpoles which one can find in England in the springtime? Most of you, I am sure, know a tadpole when you see one (sometimes he is called "pot-ladle,"or "polly-wog," or "horse-nail,") and some of you may know that a fat frog-tadpole is brown with little specks of gold, while a fat toad-tadpole is black all over; but I don't expect many of you know that there are two kinds of frog-tadpole, and two kinds of toad-tadpole, and three kinds of newt-tadpole, to be met with in England, which makes seven kinds of tadpoles in all. Now as these seven little tadpoles are all different from one another (though the two frog-tadpoles and the two toad-tadpoles are not _very_ different), we may be quite sure that they grow up into seven different little beasties. I am going to tell you something about the frog- and toad-tadpoles now and leave the newt-tadpoles for another time, for it will be easier for you if you don't have too much to remember at once. If you go into the country in springtime (the middle of March is the best time where I live, but in other places it may be a little earlier or a little later) and find a pond, or a brook which runs quite slowly, or even a hole in swampy ground which has water in it, you are almost sure to see a lump of stuff which looks like dirty grey jelly, either close to the bank or on the top of some of the weeds. If you pick up a little of this, you will find (perhaps before it has slipped out of your fingers and perhaps after) that it is full of round black eggs. [Illustration: THIS IS FROG'S SPAWN FLOATING ON THE WATER] The grey jelly is either frog's spawn or toad's spawn. If it is just a lump with no particular shape to it, it is frog's spawn, but if it is made up of small slimy ropes, which come apart from one another, and in which the eggs lie in rows like strings of black beads, it is toad's spawn. When you find toad's spawn, you may be sure that frog's spawn has been about for some time, for frog's spawn is always to be found rather earlier in the year. Whichever it may be you should take a little of it (quite a little is best) and put it in a glass jam-jar half full of water, and stand this in some bright, warm place, where it will not get knocked over, and where the sun will not shine directly on to it.