224 RECORDS OF THE AUSTRALIAN MUSEUM, 



cocoon hanging in a tree. I am doubtful if such a provision 

 exists in Nature. My experience is that a cocoon is never 

 designedly opened until the time is ripe for the young ones to 

 escape, and this is controlled by the instinct of the latter. Birds 

 do undoubtedly pull spider-cocoons and webs to pieces, but it is 

 in order B thafc they may line their nests with the material. 



Food is not necessary to spiderlings when domiciled within 

 the cocoon, and therefore no provision is made in this respect ; 

 and furthermore nothing in the shape of cannibalism obtains 

 until some time, probably a week or ten days, after the young 

 have escaped. No time is lost after escaping from the cocoon, 

 in the fabrication of a web, but it is a common one in which 

 every member of the community, males and females — at this 

 stage indistinguishable- -assist in constructing, and in which all 

 have a share. This web consists of a closely woven sheet 

 that envelopes everything within its vicinity and from which, 

 until after the second moult, thev evince no desire to wander. 

 It is interesting to note that these sheet-webs are usually densest 

 above, the cocoon (Plate lxii.), for it is there that the majority 

 of the infantile spider community will be found. If the web be 

 disturbed but slightly, immense numbers of these tiny creatures 

 will rapidly descend by means of their drop-lines (which are 

 emitted as they fall) and hang dangling in the air. For about 

 a fortnight the spiderlings live together gregariously, but the 

 migratory instinct then manifests itself. Each individual that 

 has escaped the dangers, including cannibalism, with which tin; 

 life of an infant spider is beset, assumes the attitude common to 

 the Araneidse prior to the aeronautic flight. In some species the 

 eight legs are so spread as to describe a circle, the abdomen is 

 then depressed and silk is voided, the animal turning round and 

 round as it does so ; in this way a " foot-basket " is made, after 

 which the abdomen is raised, and a delicate gossamer thread is 

 thrown out until sufficient has been voided to carry the tiny animal 

 off. Even the calm air of a room is sufficient of itself to lift one of 

 these animals and waft it along in its current. In the Held, 

 prior to ballooning, the young orb-weaver takes up a position, 

 back downwards, on some of the retitelarian lines, and commences 

 to pay out silk as follows : — 



First the spinnerets are brought into close contact, and the 

 liquid silk is emitted ; the spinnerets are then separated by a 

 lateral motion, which breaks up the silk into fine filaments ; 

 on these filaments the air-current impinges, drawing them out to 

 a length which is regulated by the will of the animal ; and, on 

 the spinnerets being again brought together, the filaments 



