COLOR AND THE COLOR SENSE. 335 



the natural color of water ; but Dolomedes sexpunctatus, which is so con- 

 stantly found on the water, sometimes has a tint that at least well harmo- 

 nizes with that of the stream itself. 



Saltigrades follow the rule of the Lycosids; their colors, being chiefly 



black, gray, and brown, harmonize with the surfaces of rocks, trunks of 



trees, etc., upon which they habitually seek their prey. Many 



Mimetic ^f them are freely marked with yellow, and thus are also sufli- 



^^'. ciently harmonized with the color of the leaves. The metallic 



monies. ,,, ,,. ,. m ^ ■ ^ 1. 



green and blue on the fangs of some Saltigrades seem almost 

 like a leaf ambush to the body of the creature as it is observed stalking 

 its prey. This suggests the strategy most familiar from its association 

 with the lines of Shakespeare : — 



" Macbeth shall never vanquished be, until 

 Great Birnam wood to the Dunsinane hill 



Shall come asainst him." 



It is, perhaps, a not wholly untenable theory that some insects are 

 made less wary by the resemblance to surrounding foliage and the play of 

 iridescent hues from the mandibles of a stalking Phidippus morsitans, 

 for example, as it stealthily moves upon its prey. But independent of 

 the indifference of the ordinary insect to spider presence, the Peckhams 

 have taught us to find the chief service of these gorgeous frontlets in 

 courtship. But what can be their use in the female Morsitans? She is 

 such a ferocious virago that we might suspect in her an example of warn- 

 ing coloration as towards her own lovers. 



According to Emerton,^ in one species of Linyphia from Weyer's Cave, 

 Virginia, the colors and markings of some specimens are as bright as on 

 spiders of the same family living in cellars and sliady woods. 

 Color o r|,jj^, other five species are pale in color. On the supposition 

 Spiders ^^^^^ '^^^ these species drifted from the outside world into the 

 caverns, we must reason from such a fact either, that the species 

 retaining a normal color had been domesticated in the caverns at a much 

 more recent date than the others, or that it was possessed of greater power 

 to resist the changes consequent upon its changed environment. 



The influence of cave life upon Anthrobia mammouthia appears to be 

 manifest in this lack of color. Two young Anthrobias were hatched May 

 3d for Professor Packard, who describes the whole bodj"-, including the 

 legs, as snow white, with the legs much shorter than in the adult state. 

 The adult in life is white, tinged with a very faint flesh color, with the 

 abdomen reddish. In some specimens the abdomen has beneath several 

 large transverse dusky bands. Linyphia subterranea as observed living 



' "Xotes on Spiders from Caves in Kentucky, Virginia, and Indiana," .Vmerican Nat- 

 uralist, Vol. IX., page 278. 



