| Some animals have eyes that enable them to see | | | | used as periscopes. This is a favorite food of certain |
| around corners; some have eyes on the ends of each | | | | fishes. Its eyes are on long tentacles, enabling it to hide |
| of five arms; some have eyes on two tall 6talks | | | | under a rock or shell and risk only one eye until it learns |
| projecting above the body. There are some animals | | | | whether or not a hungry fish is nearby seeking a |
| with two eyes that can look neither forward nor | | | | young lobster dinner. The eyes of t h e lobster and the |
| backward, because one looks to one side and one to | | | | crayfish are also on stalks, but these stalks are not so |
| the other. Some fishes see forward and backward at | | | | long. This mounting serves mainly to allow the eyes to |
| the same time; some insects can look up and down at | | | | be pointed in different directions. The eyes of |
| the same time. But there are fishes that can look only | | | | daddy-long-legs, supposed by many people to be a |
| upward; some that have eyes that migrate; some | | | | true spider, are on stalks that project above the body. |
| deep-sea fishes that must furnish the light for their | | | | Its proper popular name is harvestman, and its eight |
| eyes. There are some worms that have eyes all over | | | | legs show that it is a close relative of t h e spider, |
| thebody; some animals that have no eyes at all; others | | | | although it cannot produce silk for webs. |
| to which the whole body serves as one big eye. The | | | | While most animals, other than insects, have eyes |
| birds are provided with eyes with sunglass lenses-the | | | | designed to look in one direction only, there are some |
| nictitating membrane-and in some mammals these | | | | animals that have eyes that look in opposite directions. |
| membranes form effective shields from wind and dust. | | | | Whales, for example, have their eyes located far back |
| Many snails, including some commonly found in our | | | | on the sides of their heads, so that one eye looks to |
| gardens, have eyes at the end of tentacles, which are | | | | one side and one to the other. Neither eye can |
| extended or withdrawn much as a telescope is | | | | possibly see what the other one sees; neither eye can |
| lengthened or shortened. With these, a snail can look | | | | look forward nor backward because it cannot be |
| around a corner without exposing its body. If the snail | | | | moved. For this reason old whalers approached the |
| senses danger, the eyes are instantly withdrawn, and | | | | huge animals from directly ahead or astern. If a whale |
| the animal retreats into its protective shell. The larvae | | | | wishes to survey the entire horizon, it stands up in the |
| of the spiny lobster possess similar eyes that can be | | | | water and slowly revolves its body. |
