REGENERATION OF LOST ORGANS. 117 
that spiders have the power to cast off limbs at will. The first example 
may have been a coincidence of the experiment with the full time for 
moulting, when the old tegument was just ready to be cast and was at 
once rejected through the sudden shock of the hot water plunge and the 
violent death struggles. The second case may have been simply an actual 
loss of a leg by handling. 
Dr. Heineken, however, seemed to have no doubt as to the power of 
the animal to reject a leg. Moreover, he noted that the spiders which 
cast off crushed limbs were “hunters; those which retained 
them the webmakers; a difference for which he accounts by 
supposing that the former, perhaps, have the strongest induce- 
ment to the act, as an inert and powerless joint would be a greater 
inconvenience to them than the loss of the whole limb. Furthermore, 
a webmaker, being of stationary habit, is less liable to accidents than the 
hunter, which is constantly on the moye, and generally exposed. On this 
point I may remark that I have often met Orbweavers with one, two, 
four, and eyen five legs wanting, the result either of moulting mishaps, 
or of adventures and battles with assailants of various sorts. It is not 
uncommon to find males in this condition, a consequence of the unfa- 
vorable attitude of females in courtship. One also occasionally finds 
spiders with contorted legs which we would think might better be off 
than on, did the aranead have the power of self amputation. Certainly, 
these lost and wounded limbs did not prevent the spinning of snares, 
for I have seen in two cases, at least, an Orbweaver with all the legs 
wanting on one side weaving an efficient web. 
Mr. Francis R. Welsh writes me that he saw an Orbweaver, which was 
probably Epeira insularis, that had lost seven of its feet (not legs) grasp 
with its spinnerets a spiral of its web, underneath which it hung, and 
hang thereto by the spinnerets only. It did not attach a dragline. It 
afterwards hung and moved by bowing its legs over the spirals of its 
web. A. loss of this peculiar nature would probably have been occasioned 
by impeded moulting, and illustrates not only the perils of this act, but 
also the spider’s power of adapting itself to extraordinary disadvantages. 
Blackwall has published several important papers on this subject.1 But 
for the most thorough and satisfactory studies of the regeneration of 
,. excised members we are indebted to Mr. Waldemar Wagner. 
ee ble enthusiastic araneologist has pursued the entire histological 
development of certain organs, especially the legs, from the 
moment of amputation until the appearance of the new limb, and I shall 
undertake to interpret, substantially, the facts as recorded by him.? 
Self Am- 
putation. 
1See, as already quoted, Trans. Linn. Soc., Vol. XVI., pages 482-84; Proceed. Brit. Assn. 
Adve. Sci., Vol. XTV., pages 70-74, and Spid. Gt. Brit. and Ir., Introduction, page 7. 
2“Ta Regeneration des Organes Perdus chez les Araignées.” Voldemar Wagner. Bull, 
d. 1. Soc. Impér. des Naturalistes de Moscow, 1887, No. 4. 
