314 M. E. Bordage on the Spiral Groivth of Appendages 



XLIII. — On the Spiral Growth of Appendages in Course of 

 liegeneration m Arthropoda. By EdmoND Bokdage *. 



I. — In a previous communication to tlie Academy I noted 

 the spiral manner of growth of limbs in process of regenera- 

 tion among the Mantidse. I recalled the fact that this special 

 mode of growth is common to the Piiasmidge and to the 

 Blattidffi f. I should add that this peculiarity ought probably 

 to be met with in the four classes of Arthropoda and in the 

 case of different appendages:):. So far as insects are con- 

 cerned, the fact is now proved as regards the limbs. Further- 

 more, 1 have been able to convince myself that after 

 amputation the antennae of the larvai of Phasmidge {Monan- 

 droptera and Baphiderus^ grow in a spiral until the first 

 moult which follows the mutilation. 



Among the Crustacea spiral growth has been determined 

 in Cancer pagur us, Carc/nus inccnas^nud Pagurus Bcrnhardus 

 by H. Goodsir (' Anatomical and Pathological Observations,' 

 Edinburgh, 1845). 



Among the Arachnida the Araneidea show it clearly. 



In Myriopoda it has not yet been noted. It seems 

 probable, however, from what few researches have been 

 made upon regeneration of limbs among these Arthropoda. 

 It should most piobably be seen at least in Myriopods with 

 well-developed limbs, such as the Scutigera^ {Scuti'gera'). 

 The latter present a remarkable peculiarity. Before they 

 have attained their full development there can be made out 

 rolled up under the skin, owing to its transparency in the 

 terminal segment of the body, a number of limbs — limbs 

 which do not become free and rectilinear until the following 

 moult. After each moult the body of Scuti'gera gains an 

 additional segment. 



II. — I ought, however, to mention that spiral growth is not 

 met with in all Arthropoda. In the lobster^ for instance, the 

 thoracic limbs when in process of regeneration grow in a 

 rectilinear manner. This fact is the more remarkable inasmuch 



* Translated from ' Comptes Rendus,' cxxix. (1899) pp. 455-457, by 

 Will'ied Mark Webb, F.L.S. From a separate impression commuuicated 

 by the Autbor. 



t I bave just discovered that Mr. II, Brindley bad noted this manner 

 of srowtb in tbe Bbxttidffi (Brindley, ' On certain Characters of liBpro- 

 duced Appendages in Arthropoda,' p. 9, 1898). 



X llesearches, experimental as well as bibliographical, have, however, 

 shown me that this mode of growth is not met with in all the Arthropods, 

 as one would have been at Urst inclined to suppose. 



