STUDIES OF VARIATION IN INSECTS 299 



Thus 70 per cent, of the immature specimens examined had 

 all feet 5-segmented and 30 per cent, showed variations. This 

 is the same proportion as in the adults. The varying individ- 

 uals, however, are 16 males to i female. 



In another lot of individuals, 32 adults and 16 immature, of 

 Periflaneta americana collected in Honolulu, 16 of the adults 

 had all feet (not broken off) 5-segmented, while 16 had one 

 or more 4-segmented feet ; of the latter 5 have at least two 

 4-segmented feet. Of the immature individuals, 6 specimens 

 had all the feet 5-segmented, while 10 had one or more feet 4- 

 segmented. 



In a mixed lot of Periplaneta americana and Periflaneta 

 aust?'alasicB^ 18 adult individuals have all the feet (not broken 

 off) 5-segmented ; 27 adult individuals have one or more feet 

 4-segmented (eight having two 4-segmented feet and 2 having 

 three 4-segmented feet) ; 9 immature individuals have all the 

 feet (not broken off) 5-segmented and 8 immature individuals 

 have one or more feet 4-segmented (one having two 4-seg- 

 mented feet and one having three 4-segmented feet). 



In a series of 69 individuals of Leucophea surmatnensis col- 

 lected on the Island of Hawaii (Kohala Plantation) 54 adult 

 individuals have all the feet (not broken off) 5-segmented; 8 

 adult individuals have one or more feet 4-segmented (two have 

 two 4-segmented feet) ; 6 immature individuals have all the feet 

 5-segmented, while I immature individual has one 4-segmented 

 foot. 



But all these cases of 4-segmented feet are undoubtedly the 

 result of natural regeneration after mutilation. At least^ Brind- 

 ley's elaborate experiments and exhaustive review of the obser- 

 vations of other men prove this nearly to moral certainty. He 

 made hundreds of artificial mutilations of cockroach feet, and in 

 all cases a 4-segmented tarsus was regenerated. 



In the observations and experiments of Godelmann (Archiv 

 f. Entw. mech. d. Org., 1901, Vol. XII, p. 265) on Bacillus 

 (an orthopteron of the family Phasmidee), it was shown that this 

 insect, in regenerating legs, either after experimental amputa- 



1 Brindley, H. H., On certain characters of reproduced appendages in Arthro- 

 poda, particularly in the Blattidce, Proc. Zool. Soc. Lon. 1898, pp. 924-958. 



