80 Pub. Puget Sound Biol. Sta. Vol. 2, No. 37 



fixed abode under the stones, but shift with the tide, thus regulating the 

 depth of submergence. 



Since blennies were not found dead on shore their means of leaving 

 critically untenable positions was investigated. In a series of trials, in 

 which stones were turned and the blennies exposed to the sun, there was 

 a definite tendency, as the heat became severe, to seek new covering with 

 some accuracy of" movement. This was the rule, although exceptions were 

 found in which death occurred without any coordinated attempts to seek 

 cover. Jordan reports cases in which the fins were used to make short 

 hops in getting over the ground, but this was not observed in these blennies. 



Methods and materials 



Most of the experimental work was confined to individuals collected 

 on the rocky shore of Brown Island, a small wooded island opposite the 

 Puget Sound Biological Station. The collections were made by hand from 

 under stones at low tide. This was rendered doubly difficult by the eel-like 

 shape and the mucous secretion from the surface of the body of the speci- 

 mens when under excitement. These blennies were transferred, in water 

 of regulated temperature, to the laboratory directly or to a live-box made 

 partly of wire netting and floated near the laboratory. Those fish obtained 

 from the water were taken with the Puget Sound trawl furnished by the 

 Station. 



No marked difference was recorded for the reactions of the 3 species 

 which were most abundant in this common habitat and which were most 

 used. In fact, specific differences often intergrade making superficial 

 identification quite difficult. Since a comparison of species, as such, 

 seemed to promise little of value for this study, separate records were soon 

 abandoned when only reactions to existing conditions were sought. A few 

 tests with Xiphistes chirus, which is found perhaps farther off shore than 

 those named before, are not considered. 



The blenny as a rule is not very active under experimental observa- 

 tion but gives a positive reaction to the corners and bottom of the vessel. 

 In many instances this necessitates a strong stimulation to produce an 

 observable reaction. 



In most of the experiments the receptacles used were graniteware 

 pans of a rectangular shape (10x35 cm.). Heavy tin pans of the same 

 shape but a little larger were provided as covers where needed. For the 

 experiments in reaction to light, a section of the cover of the experimental 

 pan was cut out and an adjustable tin slide cover fitted into the space. In 

 this way the pan could be divided into approximately 3 equal light-areas: 

 bright sunlight, intermediate, and deep shadow. A second pan, completely 



