If you liave a snniisli in yonr aquariiiiu, notice as it moves slowly 

 about wlietlier the tin on its back is long as compared with that of 

 other fishes, and whether it is made up of the same kind of rays 

 throughout its length. Notice, too, the way in which it pushes its 

 mouth out when it eats. When a fish can push its mouth out in 

 this way, zoologists say it has a protractile mouth. Do you know 

 any other fish which has a protractile mouth ? 



In an aquarium near the one graced by the presence of Enpo- 

 'inotis gihhosus, was a pet bass. It is the one which is called 

 "small-mouthed black bass," but I do not believe the little fish 

 which I saw go into its mouth thought it very small. This bass has 

 become so tame that it will take a live fish from one's hand. 



Some Things to Observe in the Study of Fishes. 



The number of fins. 



Where you find them on the body. 



Of Avhat use the fins are to the fish. 



Whether the iins are similar throughout their length. 



Where the mouth is situated. Some fishes can take food from 

 the bed of the stream while others cannot. See whether vou can 

 tell from the position of the mouth where a fish nmst get its food. 



How many nostrils do you find on a fish ? 



Zo(")logists speak of the '' lateral line " which is found on many 

 fishes. Since it is called a lateral line it must be on the side, for 

 lateral means side. Can you find a lateral line on any of the lishes 

 in your aquarium ? 



HOW TO KEEP SALAMANDERS THROUGH THE 



WINTER. 



Junior Naturalists frequently ask whether salamanders can be 

 kept in the house all winter. Never having kept any I made some 

 inquiries of the zocjlogist. I found that he was the right person to 

 consult, since he intends to have some in his laboratory all through 

 the cold weather. He calls them salamanders, not lizards, for true 

 lizards have scales like a snake and they are not found in the North. 



448 



