46 Inheritance and Evolution in Orthoptera II 

 EXPLANATION OF PLATES. 



PLATE I. 



BBQ and JSOBG, BGQ and 50(70, and GCQ and CQ)CQ were photographed in pairs, 

 respectively, on the same plates and were printed in pairs. All nine kinds are here easily 

 distinguishable. 



The series of phenomena is here represented as due to the combinations of one pair of 

 allelomorphic characters, or factors, B and C, and a third character, or factor, 0, which is 

 not paired, or allelomorphic, except with its absence. 



This conception is widely different from that which represents the phenomena as due 

 to the combinations of two pairs of allelomorphic characters or factors. According to 

 Mr Bateson (2), p. 65, GQCQ, or BQBQ might be considered one character of an allelo- 

 morphic pair. 



PLATE M. 



The top row (first twelve figures) represents the patterns which breed true and cannot 

 be further analyzed. The form AA is most abundant in nature, most of the others being 

 comparatively rare. Therefoi'e it is common to find the other forms hybridized with A A, 

 though they are sometimes found pure, or in combination with others than A A. 



The eighteen figures (BE — JS) represent simple hybrids resulting from combinations 

 of the pure forms. 



The remaining fifteen figures (BFQ — CV0) represent the pure forms and their hybrids 

 carrying the melanic pattern 0, heterozygously or homozygously, as indicated. 



For an explanation of the three figures ISIS, BIS, and IIS see third instalment, 

 Journal of Genetics, Vol. vii. p. 47. 



LITERATURE CITED. 



1. Bateson, W., and Saunders, E. R. 1901. "Experimental Studies in the 



Physiology of Heredity." Report to the Evolution Committee of the Royal 

 Society. 



2. Bateson, W. 1909. MendeVs Principles of Heredity. Cambridge University 



Press. 



3. Child, C. M. 1915. Senescence and Rejuvenescence. University of Chicago 



Press. 



4. MoRCi AN, T. H., and others. 1915. Mechanism of Mendelian Heredity. Henry 



Holt and Co. 



5. Nabours, R. K. 1914. "Studiesof Inheritance and Evolution in Orthoptera. I." 



Journal of Genetics, Vol. in. No. 3, pp. 141 — 170. 



