The Inheritance of Colour in Carausius morosus. Ill 



the accidental fertilisation of females. We raised altogether after this 

 several thousand insects, and amongst these six males and one gynandro- 

 morph appeared, which were at once detected and removed. Our results are, 

 therefore, concerned with parthenogenetic inheritance. 



The insects were kept in glass cylinders covered at the top with muslin, 

 and were fed on branches of privet, the ends of which were immersed in 

 small tubes of water. In this way the food plant was kept fresh until all 

 the leaves had been devoured. The eggs, which resemble small round seeds, 

 drop to the bottom of the jar ; they can be preserved dry in pill boxes for 

 months without injury: in fact, they normally pass through a resting period 

 of four or five months. Later, however, we found that it was advisable to 

 spray them once a week — for in this way a larger proportion of larvae 

 hatched. 



During the time of hatching the atmosphere in which the insects live must 

 be kept thoroughly moist. There is considerable mortality during the 

 hatching — many insects die with the hinder end still caught in the egg shell. 

 By keeping the atmosphere moist this mortality is very much reduced. 



Females were isolated from the fourth or fifth moult and reared to maturity. 

 Their eggs were then collected and raised to maturity, and the proportion of 

 colour varieties ascertained. Although the certainty of non-fertilisation 

 only extends back one generation, the accordance of the results obtained 

 with those obtained before the presence of males was suspected not only 

 confirms our belief in the reliability of the results which we have obtained 

 but tends to prove the extreme improbability that the accidental fertilisation 

 of a female vitiated our earlier results. 



Colour Varieties of the Adult Female. 



No less than 10 grades of colour can be distinguished in the adult female, 

 viz. (1) green, (2) olive-green, (3) green suffused with brown, (4) green 

 dappled with brown, (5) yellow, (6) yellowish brown, (7) red brown, (8) hazel 

 brown, (9) dark brown, (10) brownish black. Of these Nos. 1-4 are to be 

 reckoned as green. We have already seen that all varieties of green evidently 

 represent the modification of this tint by increasing amounts of brown 

 pigment. Nos. 5, 6, and 7 are characterised by the prominence of the 

 yellowish-red pigment, whilst Nos. 8, 9, and 10 belong evidently to the 

 brown type and differ only in the intensity of their pigmentation. Six of 

 the varieties are shown in fig. 1. In this figure also the scarlet coloration 

 denoting sexual maturity is seen on the inner surfaces of the forelegs. 



K 2 



