598 



REGENERATION AND GROWTH 



TABLE 4 



DIRECTION OF PROGRESS OF REGENERATION: RECORDS AND INTERPRETATIONS 



(a) Centrifugal 



(2) Particular portions or tissues 



Isopoda and Amphipoda antenna, proximal portion 



Cambarus 



Arthropoda 



Amphibia 



General 



pleoplods 



limbs, mesodermal tissues 



limbs, skin and connective 



tissues, 

 epidermal organs 



Zeleny, 1907; Haseman, 

 1907; Przibram, 1909, p. 99; 

 Paulain, 1938 

 Przibram, 1909, p. 99 

 Child and Young, 1903 

 Tornier, 1906, Schaxel, 1921 



Korschelt, 1927, p. 328 



(3) Particular stages of the process 



Amphibia limb cell-proliferation 



General 



Asellus 



histogenetic induction 

 limb, inflation at eclosion 



Litwiller, 1939; Liischer, 

 1946; Chalkley, 1954 

 Schotte, 1939 

 Needham, 1943, p. 58 



that the rate would be very high in the active region. Under these conditions pro- 

 Hferation continues until towards the end of regeneration, in contrast to the 

 process in tail-regenerates of AnneUds (Moment, 1953), where it is completed 

 very early, while the blastema is very small. 



In Annelida the division-spindles are very regularly orientated relative to the 

 axis of the body (Berrill, 1952), as in early ontogenesis, but no great regularity 

 has been described in other instances. A diurnal cycle of mitosis-rate has been 

 recorded (Litwiller, 1940; Jaffe, 1954). As in normal growth (Bullough, 1948) 

 the maximal activity is in the late night or early morning. In Arthropoda prolifer- 

 ation is geared more or less closely with the moult-cycle (Paulain, 1938; Char- 

 niaux-Legrand, 1951; O'Farrell and Stock, 1954). 



Cell-number increases more rapidly than the absolute size of the regenerate and 

 the cells become both smaller and more crowded (Litwiller, 1939). However the 



