the C6'/()?/7\<; 0/ Tcalia crassiconii«!. 617 



quantities of mucus wliich pour from the tissues of Tealia 

 when liaiKlletl for the purpose. However, we still hope for 

 a definite result, when a suitable modification of method and 

 apparatus has been devised. 



Besides any physiolog'ical function o£ the body-pigments, 

 the general colour-schemes o£ contrasting patches of colour are 

 to be regarded as protective in virtue of their " obliterative '^ 

 value. Further, the habit of dressing seems to have a double 

 protective function — firstly, as concealment and, secondly, 

 as a check against dessication during ebb-tide. Similarly, 

 the uniform brownish-olive tint of certain shore IWdice 

 serves well for concealment, but it is impossible to detail 

 every type of colour-pattern adopted by this protean 

 species. 



The varied colour-schemes of the tentacles and disc, together 

 with the indefinite outline produced by the markings and dispo- 

 sition of the expanded tentacles, would seem to be a camouflage 

 of still greater "aggressive" value. Confirmation of this is 

 obtained by the following experiment : — Paint an expanded 

 Tealia on a cardboard disc, shading in the natural background 

 between the tentacles ; cut out the coloured part of the disc and 

 fix it on the top of the spindle of a hand-driven centrifuge, and 

 spin comparatively slowly, when it will usually be found that 

 the colours of the painting complement each othei-, giving the 

 appearance of a white or faintly bluish disc. Sometimes when 

 the primary disc-bands are strongly marked they form, when 

 being spun, a reddish ring. The conclusion drawn from this 

 experiment is that the camouflage-value of the general colour- 

 scheme of the oral surface is very great, and is such that 

 animals of imperfect powers of vision (e. ^.,Amphipods) would 

 fail to detect, visually, any danger from the presence of an 

 anemone and swim straight into its clutches, which is exactly 

 what normally happens. In the case of Tealice with very 

 strong red markings on the disc, such markings might be 

 '' warning-coloration,'^ and any creature seeing tlieni and 

 reacting would probably go straight into the outspread 

 tentacles, in which case the final effect is to be regarded 

 as, primarily, aggressive and, possibly, secondarily, warning 

 (c/. Fleure and'Walton, 1907, p. 218). 



The facts that Tealice frequent sheltered crevices and 

 expose the oral surface chiefly during flood-tide, when even 

 the few feet of sea- water covering them cut off some light, 

 tend to enhance the camouflage-value of the oral colour- 

 schemes. Innumerable as the colour-patterns of the oral 



Aivi. (&; Mag, N. Hist. Ser. 9. Vol. xi. 10 



