STRUCTURE, FUNCTIONS AND (ECONOMY OF ARANEIDEA. 73 



li. A young male Tegenaria civilis had the right palpus amputated at the 

 axillary joint on the 9th of June IS^l. On the 13th of the following July it 

 cast its integument and reproduced the right palpus, which, though small, 

 had the digital joint very tumid. It moulted again on the 20th of August, 

 in the same year, when the dimensions of the right palpus were augmented, 

 the radial joint Avas provided with an apophysis, and the sexual organs were 

 developed. The organization of the right palpus was perfect in all its parts, 

 but they Avere smaller than the corresponding parts of the left palpus. 



15. On the 25th of June 1841 a young male i^rassMsserz'ceM* had the cubital, 

 radial and digital joints of the left palpus amputated, the digital joint being 

 very tumid. It moulted on the 16th of the ensuing August and reproduced 

 the left palpus, of a small size ; the radial joint was provided with an apo- 

 physis, indicating the mature state of the spider, but the sexual organs were 

 not reproduced. 



16. A young male Ciniflo ferox had the right palpus amputated at the 

 axillary joint on the 2nd of July IS^l. On the 19th it moulted, but the 

 stump only of the mutilated part was produced. On the 28th of the same 

 month the left palpus was amputated at the axillary joint. The spider 

 moulted again on the 28th of the ensuing August, when both the palpi, of a 

 small size, were produced. 



17. The anterior leg on the left side of a young female Tegenaria civilis 

 was amputated at the coxa on the 1 st of September 1 842. This spider was 

 dissected on the 14th of the following October, when on the point of moult- 

 ing, as was evident from the deepened hue of the integument and from the 

 perfect structure of the tarsal and palpal claws, visible through it. The an- 

 terior leg on the left side, which was reproduced, was complete in its organi- 

 zation, /^ths of an inch in length, and was curiously folded in the integument 

 of the old coxa, which measured only gJ^th of an inch in length. 



18. A young male Tegenaria civilis had the posterior leg on the left side 

 amputated near the middle of the tibia on the 24th of April 1843, when it 

 moistened the tarsus of the third leg on the same side with saliva and re- 

 peatedly applied it to the mutilated limb. Being about to moult, this spider 

 was dissected on the 5th of the ensuing June ; the posterior leg on the left 

 side, which was reproduced, was found to have its tarsal and metatarsal joints 

 folded in the undetached half of the integument of the old tibia. 



A recapitulation of the more remarkable results obtained from the experi- 

 ments, elucidated in several instances by additional facts and observations, 

 will not, it is presumed, be deemed superfluous. 



Physiologists, in conducting researches relative to the reproduction of the 

 limbs of spiders, seem to have limited their investigations to the legs of those 

 animals ; whereas, in the experiments detailed above, the palpi and spinners, 

 as well as the legs, were operated upon ; and all these parts are found to be 

 renewed, and afterwards to have their dimensions enlarged at the period of 

 moulting only ; it appears also that if a part of a limb be amputated, as the 

 tarsus of a leg or the digital joint of a palpus, the whole is reproduced, all the 

 joints of the new limb, though small, being proportionate to those of the cor- 

 responding limb on the opposite side, with the exception of the digital joint 

 of the palpi of male spiders when the sexual organs are not reproduced, which 

 is usually somewhat modified in size and form by that circumstance. 



At the penultimate moult of male spiders the digital joints of the palpi be- 

 come very tumid, in much the greater number of species, by a sudden and 

 rapid advance towards development in the sexual organs, and should those 

 parts be detached during the interyal which elapses between that and the 

 succeeding moult, though the palpi, indicating by their organization that the 



