SWEET PEA ' AUDREY CRIER. 



139 



that the salmon-tinted pink of Audrey Crier is due to the three combinations 

 of factors given above. 



Is Audrey Crier then utterly unfixable ? I think it would be almost 

 impossible after so many years to select a fixed stock from those now in 

 existence, but if any one were to start again, making the original cross 

 once more and working strictly on scientific lines throughout, I see no 

 reason why he should not obtain a true stock, if, as I suppose, it is homozy- 

 gous for D and R. For, as we see, there are 75 plants homozygous for y 

 and X and 3 homozygous for Y and x. Reintroducing the factor C they 



C C 



have a composition as follows : 75 C yyXX, and 3C YYxx. One third 



c c 



of these will be homozygous for C, so that 26 of the above 78 plants should 

 breed true throughout — i.e. roughly 20 per cent, of Audrey Crier in 

 F2 should breed true, but whether there is any other factor present which 

 I have not taken into consideration and- which prevents this, I cannot say. 



I put forward this purely theoretical explanation of the colour of 

 Audrey Crier with some diffidence, for I cannot claim to have made a very 

 deep study of Mendelian principles, yet my deductions approach so closely 

 to the actual facts that I am encouraged to think that they are not far 

 from the truth, and I hope that their apparent accuracy may lead some 

 one who has the time and means to demonstrate by experiment their 

 truth or falsity. _ 



ZINNIA ELEGANS. 



Apropos of the note on Zinnia elegans (vol. xxxvi. p. 848) Sir George 

 Watt, K.O.I.E., LL.D., writes: " On the hills around Simla (N.-W. 

 Himalaya), at a height of about 6000 feet above the sea, Zinnia has 

 become a wild escape from garden cultivation. It grows in large com- 

 pact patches on exposed dry grassy slopes. It is there not more than a 

 foot in height, the average hardly half that height. The flowers are 

 double and not more than the size of a double daisy. But the most 

 curious point is that all the flowers, without any exception, are uni- 

 formly of a dirty brick-red colour — a shade never seen by me in the 

 cultivated Zinnias of India or anywhere else. I don't recollect to have 

 seen any abnormal forms, except that it is not uncommon to find the 

 scape flattened out upwards and bearing more than one flower-head. 



" By way of contrast it may be added that the Dahlia has also run 

 wild in the same neighbourhood. It frequents damp wooded glades of 

 Oak and Rhododendron arhoreum, but the flowers have all become 

 single (often very large and beautiful) and of every shade from pure 

 white to the deepest maroon and purest yellow. They are, in fact, the 

 glory of the Simla glades at the beginning of the rains — that is to say, 

 they come into bloom early in June or at least one month before the 

 carefully nurtured plants of the adjacent gardens. Moreover, they never 

 wander so far afield as the Zinnias, which may be met with assuming 

 the condition of a troublesome weed of field cultivation." 



