198 Varietäten, Descendenz, Hybriden. 



types, pubescent and smooth. The former split in F.2 in the Propor- 

 tion 2 pubescent: 1 smooth. The latter in F.2 also gives both pubes- 

 cent and smooth. Potato leaf and dwarf Champion varieties when 

 crossed reverted in leaf characters to the Standard cut-leaf type of 

 tomato, indicating that these varieties have been derived by different 

 negative Variation or mutatton from the original race. The results 

 are believed to indicate that tomato varieties have originated through 

 mutations. Gates. 



Weiss, F. E., Colour Inheritance in AnagaUis arvensis L. 

 (Rep. british Assoc. Sheffield 1910.) 



In both the scarlet and the blue varieties of Anagallis arvensis 

 the throat of the corolla is of a purple colour, due to the presence 

 of a purple sap in the cells of this region; in the centre of these 

 purple cells there is a coUection of needle shaped crystals of a 

 deep blue colour. 



In the scarlet form {A. phoenicea) the bright colour of the petals 

 is due to a red sap, different in colour and in its chemical nature 

 from the purple sap found in the cells of the throat. In the blue 

 form [A. caerulea) the colour appears to be due to a blue sap, 

 though possibly the appearance is due to the presence of very 

 tinely divided particles of colour. 



Two öther varieties of the species occur, one somewhat salmon- 

 coloured {A. carnea of Schrank) and one of pale-pink colour. Reci- 

 procal crosses between the scarlet and blue forms produced F^ 

 plants wiih scarlet fiowers indistinguishable from the scarlet parent, 

 except that, in one or two flowers out of several hundred, a small 

 blue streak, noticeable on the petals, indicated the hybrid nature of 

 the plant. 



In F2 segregation is complete, and no intermediate forms were 

 obtained. The iiambers obtained however depart somewhat from the 

 simple Mendelian ratios, the F^ from A. caerulea ^y^A. phoeiücea ^ 

 having given 62 red, 8 blue; while the F2 from the reciprocal cross 

 has given 25 red, 2 blue. 



When the pale-pink form is crossed with the blue, the latter 

 colour is again found to be recessive. The F, from this cross has 

 not yet been obtained. 



The complete dominance of the red colour in the crosses between 

 A. phoenicea and A. caerulea is not in accord with the Suggestion 

 that A. carnea is the h3'-brid of these two forms. It is more likely 

 that the last-named is a pale variety of the scarlet pimpernel. Expe- 

 riments are now being carried on to settle this point. 



R. P. Gregory. 



Weiss, F. E., Note on the Variability in the Colour ofthe 

 Flowers of a Tropaeolum Hybrid. (Mem. and Proc. Manchester 

 lit. and phil. Soc. UV. No. 18. 1910.) 



A plant was observed to produce flowers differing from one 

 another in the degree of development of the red sap, the types of 

 flower produced ranging from a yellow flower devoid of sap colour, 

 through a series of blotched and parti-coloured flowers, up to scarlet 

 flowers in which the red sap is evenly distributed over the whole 

 petal. The arrangement of the different kinds of flowers on the 

 branches was apparently quite irregulär. 



Flowers of the vari'ous kinds were self-fertilized , and the resul. 



