A. W. liKLLAMY 09 



This ratio of 4:2:2:2:2:1:1:1:1, or, when the single and double 

 doses of H are counted in the same class as was done for (9.18) and 

 others, of 6 : 3 : 3 : 2 : 1 : 1 , is actually a 9:3:3:1 ratio ; or better, as 

 has been emphasized by Nabours-('l7), the 9:3:3:1 ratio is actually a 

 •1:2:2:2:2:1:1:1:1 ratio. 



Discussion. 



The chief purpose of thi.s paper has been to record the inheritance 

 behaviour of several colour patterns in Tettigidea which constitute a 

 system of " multiple allelomorphs " ; and of another pigmental character- 

 istic (H) "which exists in connection luith and in addition to the other 

 patterns." 



The theory of multiple allelomorphism as set forth by the Morgan 

 school, jjostulates that the determiners for all the characters of a given 

 system of multiple allelomorphs shall have identical loci in a pair of 

 h(jmologous chromosomes. There may be as many sets or groups of 

 characters as there are chi-omosomes in the matured gametes. It is 

 stated that the same results may be explained equally well by assuming 

 that there is complete linkage, i.e. that the determiners lie so close 

 together in the chromosomes that crossing over never takes place, and 

 that the end results would be the same in either case. 



If one wishes to interpret these results in the light of this hypothesis, 

 it may be assumed that the " determiners " for the characters C, D, E, F, 

 and M have identical loci in a single pair of homologous chromosomes. 

 In the case of H it need only be assumed that its determiner is borne by 

 some other chromosome. H is not sex linked and is apparently, as 

 stated by Nabours for his © in Paratettuv, allelornorphic only to its 

 absence. 



This report is based upon 3,:il9 recorded individuals. 



EXPLANATION OF PLATE III. 



Five " forms " of Tclliijidea parfipciiiiis are represented iu the first five figures on the 

 Plate, viz. CC, DD, EE, FF, and MM. The six figures, CE, CF, CM, DE, DF, EF, 

 represent hybrids between certain of the preceding forms. The remaining six figures show 

 the result of the addition of. the factor H. For fuller explanation see text, p. 57. 



