CORRELATED GROWTH-CHANGES 



125 



upon growth, have been recorded by Gabritchevsky (1930) 

 in his experiments on regeneration in spiders. In successive 

 moults, the legs of the species used by him pass through a 

 r e ad i 1 y -char- 

 acterized series 

 of develop- 

 mental stages. 

 If a leg be 

 amputated, its 

 regeneration is 

 accompanied by 

 alterations in 

 this sequence in 

 the neighbour- 

 ing legs. Some- 

 times the nor- 

 mal sequence 

 is accelerated, 

 sometimes re- 

 t ar ded ; in 

 either case, 

 compensa t o r y 

 effects in the 

 other direction 

 may be subse- 

 quently pro- 

 duced. Gabri- 

 tchevsky's re- 

 sults to date do 

 not permit us 

 to say why 

 either of these 

 two opposed 

 effects may be 

 found ; we may 

 anticipate that 

 the cause will 

 prove to lie in 

 the rapidity of 



regeneration and the time before moulting at which the oper- 

 ation was carried out. 



Przibram (1917) carried out an elaborate investigation on 

 regeneration of legs in the Mantid Sphodromantis bioculata. 



a 



s 



o 



i». 



o 

 o 



k. 



o 



<3 



•a 



K 

 Si. 



n. 



a 



Q 



O 



k. 

 &o 



<u 



a 



^-. 



s 



<u 

 Si. 



3rd. 



Mxpd 



1st. 



2nd. 



3rd. 



4th. 



5th. 



pereiopods. 



Fig. 67. — Correlated changes of growth-rate in struc- 

 tures immediately anterior and posterior to a local 

 region of high growth-intensity (male chela) in the 

 prawn, Palaemon cardials. 



The graph represents the growth-rate (% increase for 100% increase 

 in carapace length) of various appendages in males and females. 



