AMPHIBIANS. 19 



and dust shot, are very effective means of collecting large series of 

 frogs. 



The tailed amphibians are rather slow in their movements, and 

 when on land they can be readily picked up bj^ hand. ^Alien ob- 

 served in the o]>en water they may be easily caught in the dip net. 

 Digging up with the net the leaves and mud from the bottom of 

 ponds in woody places will usually result in the finding of several 

 specimens. 



Specimens may be carried from the field in a minnow pail in 

 which there is enough water to keep them moist. When it is neces- 

 sary to keep several collections separate, the animals may be placed 

 in cheesecloth bags with some wet moss. Small specimens should 

 be kept separate from the large ones so that the former may not be 

 injured. 



Keeping Live Material: It is often desirable to keep amphibians 

 alive in the laboratory and the following suggestions may be found 

 useful. Toads and frogs may be kept in large glass jars, covered 

 over the top with netting and containing some moss and a small 

 amount of water. Flies and earthworms placed in the jars will be 

 eaten readily. The frogs should be sorted according to size and 

 those of approximately the same size placed in the same jar, other- 

 wise the large individuals will eat the smaller ones. 



The small tailed amphibians which are terrestial in habit, Hemi- 

 dactylium seutattini and PJetliodon erytlironotus, may be kept in 

 l)acteria dishes with a little damp moss. If the moss is renewed fre- 

 (juently they will find sufficient numbers of insects and larvae in it 

 to keep them in good condition. The Ambystomas and Diemifctilus 

 riridescens should be kept in dishes containing moss, bark and dead 

 leaves with some water at one side, so that thev mav enter it at 

 will. They will eat insects, worms and small pieces of meat if 

 ottered to them. Small tadpoles placed in the water will furnish 

 food for Dieini/ctilus viridescens. 



The aquatic forms will need a larger supply of water. Xecturus 

 should be kept in a tank containing running water to the depth of 

 two or three inches. There should be some floating plants or other 

 objects under \\hich they may partially conceal themselves. Raw 

 beef cut in small pieces and presented on the end of a fine wire will 

 sometimes be taken as food. If this method of feedins: is not sue- 

 cessful, small frogs and fish may be eaten if placed in the tank. 

 Necturus will remain in good condition for a few weeks without 

 food. 



Preservation of Specimens: Amphibians which are to be per- 



