104 



AMERICAN SPIDERS AND THEIR SPINNINGWOKK. 



Lost in 

 Moulting. 



specimens without one or more limbs, also with distorted and abbreviated 

 limbs. I have frequently found males lacking several legs. The theory 

 commonly adopted is that in most of tliese cases the loss has 

 Mou ing j.gg^^jHg^| fj.Q^j conflicts, perhaps among rival lovers in attendance 

 upon the same female. Something of loss may be attributed to 

 this cause, but I am satisfied that in a much larger degree losses and mal- 

 formations are due to the accidents of moulting. 



One example I may cite, the loss of two limbs experienced by a large 

 tarantula which I had kept under observation. This spider lay upon its 

 back in the araneary during part of the time of moulting, and on its side 

 during the remainder thereof. The skin was cast by a succession of 

 movements of the body or parts of the body recurring at reg- 

 Limbs ^^i.j^j. intervals, reminding one of labor pains among mammals. 

 For some reason two of the legs refused to separate from the 

 skin, and after a prolonged struggle they were broken off at the 

 coxa>, and remained within the moult. (See Fig. 64.) One foot of another 



leg shared the same 

 fate. This moult oc- 

 curred in the spring ; 

 during the latter part 

 of August of the same 

 year the spider again 

 moulted. The moult 

 was a perfect cast of 

 the animal, the skin, 

 spines, claws, and the 

 most delicate hairs 

 showing, and their cor- 

 responding originals 

 appeared bright and 

 clean upon the spider. 

 When the castoff skin 

 was removed the dissevered members were lacking thereon, but on the 

 spider itself new limbs had appeared, perfect in shape but smaller than 

 the corresponding ones on the opposite side of the bodj'. The dissevered 

 foot was also restored. The rudimentary legs had evidently been folded 

 up within the coxse, and appeared at once after the moult, rapidly filling 

 out in a manner somewhat analogous to the expansion of wings of insects 

 after emerging. ^ 



It is possible that the tarantula " Leidy " was too much exhausted by 

 long previous fasting to endure the severe strain upon the organism in 

 the act of moulting, althougli judging from the disjecta membra of the 



Kli^. 64. 



Cast skin of Mygale, showing stumps of legs broken 

 during moulting. 



' See Proceedings Academy of Natural Sciences, Philadelphia, 1883, page I'.ni. 



