928 MK. H. H. BBINDLET ON EEPEODtJCED [l)eC. 13, 



point (Vappui was always necessary for rupture, but in other 

 respects his results were very varied. Autotomy did not always 

 occur in a series of individuals of one species, the latent period 

 between stimulus and loss varied greatly, and the results were 

 greatly affected by age and the mode of stimulus, as well as by 

 the particular genera and families employed. Parize (63) has 

 also observed diversities of this kind. In Tarantula it has been 

 shown by McCook (57) that the struggles at ecdysis may result in 

 loss of limbs either at distal regions or at the suture. Blackwall 

 (3), who made numerous experiments on regeneration, has not 

 described either autotomous or eventual loss of the stumps of 

 limbs left after partial amputation. More recently Wagner (75, 

 76) has made experiments on Tarantula with the result that 

 section of a leg about its middle is nearly always followed by the 

 animal tearing out the stump up to the suture, an act which seems 

 to be performed in order to prevent loss of blood, which is, as in 

 other Arthropods, great at the point of section, but very slight at 

 the suture. His experiments also lead him to the important and 

 suggestive conclusion that in cases where the stump is not torn off 

 all its tissues degenerate up to the suture, and that therefore 

 regeneration takes place only from the coxa. But as there is no 

 doubt that there is among Spiders much variation of autotomy, it 

 is possible that in some forms regeneration may commence from 

 points distal to the suture. 



Scorpionida;. — Mr. B-. I. Pocock informs me that it is practically 

 certain that autotomy does not occur in this group, nor has any 

 account of the regeneration of lost appendages been published. He 

 has, however, examined certain specimens in the British Museum, 

 w hose history is unknown, but which are almost certainly instances 

 of partial regeneration of the ivalking-legs. Two of these cases 

 have recently been kindly shown to me by Mr. Pocock, and certainly 

 suggest that in Scorpions regeneration commences from the actual 

 seat of injury and is not confined to one particular region of a limb. 



Myeiapoda. — On the regeneration of appendages in Myria- 

 poda but few observations are recorded, and none are of recent 

 date. Autotomy does not seem to occur in this group. Newport 

 (61) found that in Julus the stump of an antennal joint 

 was retained, and he concluded that reproduction commenced 

 from the point of amputation, for after ecdysis the regenerated 

 extremity could be clearly distinguished by its lighter colour. 

 In both Julus and Lithobiiis he observed legs regenerated from the 

 coxa after loss brought about by unknown causes. 



IjfSECTA. — Among Insecta the reproduction of lost appendages 

 is known to occur in certain genera of CoUembola, Orthoptera, 

 Heraiptera, and Lepidoptera. 



CoUembola. — Very little is known concerning the life-histories 

 of the CoUembola, but it appears that the ecdyses and the power 

 of reproducing the appendages are continued after full growth 

 and sexual maturity have been attained. In these respects, 

 therefore, the group stands in contrast with other Insecta. In 



