78 AMERICAN SPIDERS AND THEIR SPINNINGWORK, 



iiiid as a consequence could only si)in very imperfectly. It was observed 

 to follow the habits of the hunting spider, which does not build a web, 

 but catches its prey by stalking. This change of habit was only tem- 

 porary, as the spider recovered its legs after moulting, i Mr. Darwin also 

 alludes to this incident. 



My observations are wholly contradictory of this. I have placed u})on 

 my vines an Epeira domiciliorum that had lost all the legs on one side, and 

 found it to weave a serviceable web, although necessarily some-^ 

 Spinning ^yliat imperfect. It hung upon its snare and trapped flies with 



f., ^.^ ^' fair success. I have often noted similar defects in various spe- 

 tilation. .^ .1,, i,T»TT^ , ■ ^ 



cies always with the same result. Mr. Komanes inference as 



to the plasticity of instinct needs a little more confirmation. Indeed, 

 the inference was long ago fully exploded by the observations of Dr. 

 Heineken, a surgeon in the Island of Madeira during the early part of 

 this century. This gentleman, in order to test the ability of orbweaving 

 spiders to spin after mutilation, removed at intervals, successively, the legs 

 of various individuals, with the following results : Epeira (Argiope) fasciata, 

 with all the legs removed except the second and last on the left side and 

 the last but one on the right side, thoroughly mended its web wlien two- 

 thirds of it had been torn away. It maintained the same position and 

 attitude as before mutilation, and in every respect had the manner of an 

 Orb weaver. 



Another Epeiroid spider had all the legs removed except the first on 

 the right side and the second and last on the left side, leaving the spider 

 with but three legs. On the following day, filaments appeared in several 

 directions. These were constantly added to, and in the course of two weeks 

 a geometric web was formed equally perfect, but more sparing in quantity 

 than one made by a spider in the same species and under the same made 

 of confinement, but healthy and unmutilated. The entanglement and taking 

 of flies, and the conduct of the two spiders was in every respect similar. 

 They were confined in large glass jars. A number of individuals were 

 experimented u})on with the same result. In the case of one tubemaking 

 spider, the number of limbs was reduced to two, and the web entirely de- 

 stroyed. Even then enough web was spun to cover the spider imperfectly 

 and occasionally to entangle an exhausted fly. It lived for five weeks after 

 mutilation.^ 



^ Transactions Linnreau Society, Vol. XI., page 393. 



- Dr. Heineken, On tlie I'eprodnctioii of Menihers in S])i(lers and Insects. Zoolo<>ioal 

 .lournal, Vol. IV., iJa^e -428. 1S2S-2!). 



