1918 Miles; on Behavior of Blennies 81 



covered, was used as a control. For experiments in color reaction, a remov- 

 able frame was provided which held 3 squares of glass, respectively, red, 

 green and blue. 



A device for studying the reaction to the color of the background was 

 a floating live-box containing 5 colored compartments connected by square 

 openings about 10 cm. in width. The box was designed by Professor 

 E. Victor Smith of the University of Washington. It was about 15 dm. long, 

 with ends approximately 3 dm. square. The bottom, sides and partitions 

 were of wood. The sides contained holes covered with wire screen. The 

 top was open to the sun. The central section was painted white ; the end 

 ones red and orange, respectively. A fish placed in the white compart- 

 ment was forced to pass thru a blue one to reach the orange one, and thru 

 a green compartment to reach the red one. The bottoms of the compart- 

 ments were strewn with a few shells and stones. 



A gradient tank used in experiments in reactions to temperature 

 changes and chemicals was the same as that described by Shelford and 

 Powers (1915). It was principally of metal, had a glass front, was rec- 

 tangular in shape and measured 15x122.3 cm. with a depth of 13 cm. In 

 order to insure uniform lighting the tank was covered with a black, hooded 

 frame with openings for observation. Light was furnished by 2 candles 

 placed at equal distances from the ends at the rear of the tank. 



Response to contact (thigmotaxis) 



It was observed that few of the species used were taken in nets 

 even near shore at average tide, although hundreds were found under 

 stones at low tide. They were found under stones in the water, and in 

 live-boxes they sought shelter below sea lettuce (Ulva) or stones. Where 

 shelter could not be found they adapted the shape of the body as nearly 

 as possible to the surface of some submerged object and remained motion- 

 less. They appeared to be positive to the bottom rather than free swim- 

 ming above it. 



In more definite experiments half a pan was laid with flat stones and 

 the other half left bare. The experiments were performed in the dark., 

 i.e., with covers over the pans. After several trials, with diflferent indi- 

 viduals a positive reaction to stones was recorded as shown by positive 

 82.2%, negative 17.8%. The corresponding ends of the control gave 

 positive 54.8%, negative 45.2% . 



Sea lettuce (Ulva), on the other hand, produced a negative reaction 

 in the dark, as shown by positive 26.6%, negative 73.4%. The control 

 was recorded as positive 48.8% and negative 51.2%. As noted, the re- 

 action was positive in the live-box in sunlight. If we assume that light 



