Ill 



STAGES IN AN ACT OF REGENERATION 



599 



Table 4 continued 



DIRECTION OF PROGRESS OF REGENERATION: RECORDS AND INTERPRETATIONS 



{b) Centripetal 



Animal 



Nature of regenerate 



Reference 



I ) General 

 Ttibularia 



Hydra 

 Planarians 

 Annelida 

 Asteroidea 



Phoronis 

 Cambariis 



General 



whole hydranth and indi- 

 vidual tentacles 

 head-end of body 

 head-end of body 

 head-end and tail-end 



adult, body 



chela and anterior walking 



legs 

 all regenerates 



Child, 1941 p. 36 



Abeloos, 1932, p. 208 

 Brendsted, 1955 

 Abeloos, 1932, p. 208 

 King, 1 898 ; Dawydoff, 1901; 

 Morgulis, 1912; Shapiro, 



1914 



Schultz, 1903 

 Haseman, 1907 



Abeloos, 1932, p. 118 



Particular portions or tissues 



Isopoda and 



Amphipoda 



Cambarus 



Arthropoda 



Amphibia 



General 



antenna, distal portion 



pleopods, distal portion 

 limb, epidermis 

 limb, skeleton 

 internal organs 



Zeleny, 1907; Haseman, 

 1907; Paulain, 1938 

 Przibram, 1909, p. 99 

 Child and Young, 1903 

 Tornier, 1906; Schaxel, 1921 

 Korschelt, 1927, p. 328 



(3) Particular stages of the process 

 General dedifferentiation 



Asterias 

 Amphibia 



arm, determination 

 limbs, determination and 

 differentiation 



various authors 

 Child, 1941; p. 336 

 Guyenot and Schotte, 1923 

 (see Abeloos, 1932, p. 206) 



reduction in size is small by comparison with that of the blastomeres of some eggs, 

 during cleavage, and true growth no doubt begins at the outset of the P-phase. 

 Nevertheless experimental treatments appear to distinguish the phase of mainly 

 proliferative growth from the later phase of hypertrophy (Paulain, 1938, p. 308). 



In some Arthropoda, e.g. Leander (Paulain, 1938), regenerative growth of limbs is visibly 

 continuous, as in animals of other phyla but often, as in Asellus, nothing is visible externally 

 until after moulting, when the growing regenerate undergoes "eclosion" by distension 

 with blood, a more dramatic counterpart of the normal "growth" of most Arthropods. The 

 limb-regenerate of Carcinus grows continuously, though apparently slowly because it is 

 very much folded up, and therefore it also shows a marked eclosive "growth". In the cock- 

 roach (O'Farrell and Stock, 1953, 1954), and probably in insects generally, cell-proliferation 

 is restricted to a short period in the middle of each "stadium" or "intermoult". In Ar- 

 thropods with long stadia this middle period is a much longer fraction of the whole, and 

 the pre- and post-moult arrests of growth therefore are less evident. 



The relationship between growth and differentiation needs further investigation 

 (Needham, 1952). The results of differentiation become increasingly evident in 

 the later stages of regeneration but so do the results of growth, though the growth- 

 rate is maximal very early. The early incidence of determination implies that 



Literature p. 641) 



