THE BEHAVIOR OF FUNDULUS 



347 



In this experiment a dam was thrown across a long narrow 

 tide-pool running parallel with the coast-line as shown in figure 

 3. In this way approximately 150 specimens of Fundulus 

 majalis of various sizes were enclosed. The sand-bar between 

 the pool and the sea varied in height from 10 to 15 cm. This 

 bar rose rapidly along the edge of the pool on the sea side, but 

 on the opposite edge of the pool the inclines was very gradual : 

 so that the elevation at the end of the dam on this side was 

 only 3 cm., while on the sea side it was over 10 cm. 



Observations were continued for 20 minutes. During this 

 time nearly 50 specimens escaped by traveling overland around. 



s 



Fig. HE Outline of a long, narrow tide-pool with a dam thrown across near the 

 middle. This pool had a maximum width and length of 2 and 24 meters 

 respectively. It contained approximately 150 funduli, most of which escaped 

 by traveling overland, against a moderately strong wind, around the end of 

 the dam on the land side, xy. T,tide-pool; o, outlet; S, sea; s, sand-bar; 

 d, dam; m, n, x, y, points mentioned in the description. The arrow indicates 

 the direction of the wind. 



the end of the dam from x to y, i. e. on the land side where the 

 elevation was least. These specimens were opposed in their 

 locomotion on land by a fairly strong wind. A few escaped at 

 the opposite end of the dam, going overland from m to n. And 

 two crossed the sand-bar taking a direct course to the sea. A 

 few also came out a short distance elsewhere but all of these 

 returned to the pool. 



The results obtained in these two experiments and others show 

 that Fundulus tends to leave the tide -pools near the original 

 outlet. Relatively few were seen to attempt to escape else- 

 where in spite of the fact that the incline of the bottom was usu- 

 ally much more gradual in many other places. They also show 

 that there is a tendency to select the lowest place near the out- 

 let. This is particularly evident in experiment 2. Ordinarily 

 these creatures leave the pools on the side of the outlet nearest 

 the sea but in this case they left on the side nearest the land 

 where the elevation was much less than on the opposite side. 



