EXPERIMENTS IN INHERITANCE OF COLOUR IN LEPIDOPTERA. 261 



Old Red Sandstone Rocks at Rlnjnie, Aberdeenshire . Final Report of 

 Committee (Dr. J. Hoene, Chairman; Dr. W. Mackie, Secre- 

 tary; Dr. J. S. Flett, Dr. W. T. Gordon, Dr. G. Hickling, 

 Dr. E. KiDSTOxN, Dr. B. N. Peach, Dr. D. M. S. Watson) 

 appointed to excavate Critical Sections therein. 



Dr. W. T. Calman and Mr. D. I. Scourfield have continued their examination 

 of the microscopic sections of the plant-bearing cherts discovered by Dr. Mackie 

 in the Old Red Sandstone at Rhynie, Aberdeenshire. The following Report on 

 the results of their investigations has been furnished by Dr. Caiman :— ' A large 

 number of sections and chips have now been studied by Mr. Scourfield, and 

 drawings have been made of the more important remains. It has not been 

 possible to discover any regularity in the way in which the specimens are 

 distributed in the chert, or to correlate their presence with anything visible to 

 the naked eye in hand specimens. Although the remains are of the most 

 fragmentary kind, it has been possible to determine with fair certainty the 

 more important characters of the body and limbs. We are now convinced that 

 all the remains belong to a single species which is most nearly related to the 

 Anostraca, although it differs in important morphological characters from the 

 recent representatives of that order. It is hoped to discuss these remains 

 at greater length in a memoir which is now in preparation. A few fragments 

 of limbs and body-somites of a much larger Arthropod have been observed. 

 There is some evidence to suggest that these may belong to a Diplopod, but it 

 is not proposed to discuss them unless further material should be discovered.' 



As sufficient material has been collected for further examination, the balance 

 of the grant from the Royal Society has been returned. The Committee may 

 now be discharged. 



Experiments in Inheritance of Colour in Lepidoptera. — First Report of 

 Committee (Prof. W. Bateson, Chairman; Hon. H. Onslow, 

 Secretary; Dr. F. A. Dixey). 



Spiloxania mendica and var. rustica. — The white variety of the male is incom- 

 pletely dominant. About 400 insects were raised from the following types of 

 mating : — DR x RR, DD x DR, and DD x RR. Eggs were obtained from a 

 number of pairings of DR X DR, which will emerge next year, 1921. These, 

 with the previous records, should be sufficient to elucidate the nature of the 

 inheritance. Owing to the great colour variation of the F, generation, readings 

 of the colour of each individual are being made with the ' Tintometer ' to show 

 the colour distribution. 



Boarmin consortaria and var. ronsobrinaria. — About 200 insects were reared, 

 which confirmed the dominance of the melanic variety. The suggestion made in 

 the .7. of Gevpfics. Vol. IX. No. 4. March 1020, p. 3^9. that the intermediate 

 varietv is dominant to the type, was also confirmed. Ova, were obtained which 

 should .<!how the relationship of the intermediate to the melanic varietv next year. 



Hemerophila abruptarin and var. brunneata. — Ova were obtained from several 

 nairs in order to see whether the melanic variety behaves as a simple Mendelian 

 dominant. In the published experiments of Hamlinrr and Harris there is a large 

 excess of melanirs in matings of the type DR x RR. 



Callimorpha doviinula, and the yellow variety. — About 700 insects were raised 

 from these crosses, which completely confirm Bateson's suggestion that the yellow 

 form is recessive to the red. The insects reared will serve as material for an 

 examination of the pigments. 



Zygava fiJipeiidulre, and the yellow variety. — Larvae were reared from several 

 nairings between red and yellow varieties and from the Fi generation. The 

 larvae have not as yet pupated. 



Abraxas grossulariata and var ^^arleynta. — About 40n insects were reared 

 f ron4 matings between th© type and the melanic variety. Together with pr^vjofls 



