while the web above described which it has spun represents the more watery marginal part (become dry), even to the run-off portion with the thickened knob (which was not accidental, as it occurred in both cases), like the residue which semi-fluid substances ending in a drop leave on evaporation.  It keeps itself in position on its back by thrusting under the web below it the spines with which the anterior upper surfaces of the legs are furnished.” ...

PROTECTIVE HABITS.—­Going along with these forms of protective resemblance, we find certain habits which sometimes serve independently to protect the spider, but oftener are supplemental to color and form.  Many species hide in crevices or in leaves which they roll up and bind together at the edges.  In the Epeiridae some are like thaddeus, which makes a little tent of silk under a leaf near its web.  The young thaddeus also makes a tent, but spins its little geometrical web on the under side of the leaf, the edges being bent downward.  E. insularis has the more common habit of forming its tent by drawing the edges of two or three leaves together with strands of web; in this it sits all day, but at night descends and occupies the centre of the web during the hours of darkness.  I have often found it in this position when hunting nocturnal species by lantern light.  It is probable that in tropical countries the monkeys, and perhaps the birds, which devour these large Epeiridae have learned to recognize their webs, which are very large and conspicuous, and to trace them to their hiding places close by; and thus may have arisen the curious habit noticed by Vinson as possessed by E. nocturna and E. Isabella of destroying the web each morning and rebuilding it at night; the spider in this way gaining greater security from diurnal enemies.

Atypus abbotii builds a purse-shaped tube which is found attached to the bark of trees, and which has the external surface dark and covered with sand.  The trap-doors which close the nest of some of the Territelariae are wonderful examples of protective industry.  They fit with such absolute accuracy into the openings of the nests and are so covered on the upper side with moss, earth, lichens, etc., as to be indistinguishable from the surrounding surface.

The rectilinear lines which are stretched in front of the webs of many Epeirids are useful in taking and sending on to the spider the shock which tells of an approaching enemy.  Some spiders, when danger threatens, shake the web so violently as to grow indistinct to the eye, and others, as Pholcus atlanticus, hang by the legs and whirl the body rapidly with the same bewildering result....

A habit common to many spiders, especially among the Epeiridae, is that of dropping to the ground at the approach of danger and resting motionless among the dirt, sticks, leaves, etc., which they resemble in color.  The holding of the body in some peculiar position, as in Uloborus, Hyptioides, and the flower-like Thomisidae, is a necessary accompaniment to the color modification.