424 



Dr. Heineken on the Reproduction of 



portion of limb being at liberty : but when a crushed limb is to be cast, as it 

 is incapable, from its powerless condition, of serving as a point d'appui, if 

 placed upon a solid substance, one of the sound limbs is pressed against 

 it ; or when, from previous mutilation, but few such remain, it (the 

 crushed limb) is entangled in the web ; and the act of casting then takes 

 place after simple amputation, as the leg is only abbreviated, and not 

 enfeebled, the cut extremity is pressed against the ground or web, and 

 serves for its own fulcrum* 



In a postscript to my former observations I briefly and very hastily 

 noticed the reproduction of the antennee by a larva of a cock-roach, and 

 some wood-lice also, I think, (for I have no copy of the paper, and shall 

 therefore be excused any repetition which may occur). The latter, 

 from their habits, cannot be so frequently and easily observed as would 

 be convenient, but as far as I can ascertain, the reproduction with them 

 is gradual, and independent of moulting. On the 2d of December I cut 

 off an antenna from each of two Armadillos : on the 8th both antennse 

 were removed from two others, and one, from each of several more : on 

 the 11th they were all examined, were found to be unchanged, and placed 

 all in the same box. On the 12th of January two had reproduced per- 

 fect but colourless antennse, and rudiments were very evident in several 

 others. Within two months from the removal a dozen, including the 

 two which had been deprived of both, were found with fully-formed, 

 but pallid antennse. These observations are, I am aware, too few, and 

 were too imperfectly conducted, to establish the fact of reproduction dif- 

 fering so materially in these animals. I will not say positively that what 

 appeared to me to be rudiments might not, under a more powerful lens, 

 and a more patiently scrutinizing eye, have proved minute, but perfect 

 antennse ; neither can I assert that moulting did not take place, for the 

 exuvise might have been concealed in the rubbish in which the animals 

 lived, and have eluded my search ; or, as they are, in the strictest sense 

 of the word, omnivorous, have been eaten as soon as cast. Should this 

 have been the case, they will belong to that class where the reproductive 

 power is connected with, and confined to, the periods of moulting : but 

 on the contrary, should my conclusions be correct, to that class where 



