"Do you suppose Robinson Crusoe's cave was anything like this?" Maria asked her brother.
But the answer was, "I don't think so; you know it was not beautiful. And see here, Maria, look at those shining pendants hanging from the roof. They are as clear as diamonds. Oh, look down beside your feet; there are more of those lovely things; they are reaching up to meet those coming from above."
"What makes them, papa?"
Señor Diaz then explained to the children that there must be a great deal of lime in the rocks overhead, and that, when the water slowly filtered through the roof of the cave, it brought with it the lime which formed in these wonderful crystals.
"People pay great sums of money for precious stones," said their father, "but what could be more beautiful than these shining pyramids! The pendants hanging from the roof are called stalactites. Those reaching up from the floor of the cave are stalagmites. Do you suppose you can remember such hard words, my dear little Isabella? But come, children, I have something else to show you here."
He led the children to a little pond, in which they could dimly see, by the light of the torch, fish sporting about in the water.
"Those fishes are happy as can be, yet they are perfectly blind. I made some experiments years ago that led me to discover it. You see how dark it is. The creatures living here would have no use for eyesight, so they gradually became blind. We can only keep the organs of our body in good condition by using them."
It was no wonder the children enjoyed the day with their father, as he always had so much of interest to tell them. This evening, as they sat on the balcony, Maria was talking about the fish that lived in darkness, when Ramon suddenly exclaimed:
"Look! look! the garden is fairly alive with lights. The cucujos are giving us a display of fireworks. Let's catch them, and have some fun. Except in the rainy season, it is not often that we see so many." He ran into the house for a candle, and the three children were soon chasing the cucujos along the walks.