70 Evolution of the Double Stock 



it worth while to put these observations on record and so clear the 

 ground of any doubt which these earlier references, as they stand, might 

 throw on the validity of the conclusion expressed above. Taking the 

 references in question in their chronological order we have : 



(1) Sowerby's illustration of Cheiranthus incanus in the first and 

 second editions of English Botany^. The specimen figured was obtained 

 in 1808 by lowering a boy over the cliffs near Hastings. It is on record 

 that Hooker was present on the occasion as well as Borrer (who with 

 Dawson Turner discovered the plant in this locality in 1806), and it may 

 be inferred from the account that only the one specimen was taken. The 

 illustration represents a simple raceme on which only four flowers are 

 as yet open, the remainder being still in the bud stage. The first (lowest) 

 of these is shown viewed from the back with only calyx and corolla 

 visible. Both appear to be normal. In the succeeding (second) flower 

 there are nine petals of about normal size and an additional very small 

 one in the centre where only three out of the four long stamens appear. 

 The third flower is shown with five petals and the anthers of the four 

 long stamens. In the fourth flower we have, so far as can be judged, 

 again a normal single. Now it is to be noted that in the third edition 

 this illustration is replaced by a drawing of a plant obtained from the 

 Isle of Wight. [The plant had been lost apparently from the Hastings 

 locality as far back as 1835^.] I have been unable to trace in botanical 

 writings any allusion to the reason for this substitution and although 

 many of Borrer's specimens are preserved at Kew, I cannot find that the 

 1808 Stock is among them. It may be presumed, I think, that it is not 

 now in existence. The probable explanation of why it was discarded will 

 appear presently. 



(2) A statement in Hopkirk's Flora Anomala^ (1817), a work brought 

 to my .notice by Dr Agnes Arber. The passage runs as follows : " Of 

 multiplicate polypetalous flowers we have many examples, as Gistus 

 helianthemum, Anemone nemorosa, Sanguinaria Canadensis, Tormentilla 

 officinalis, Hibiscus rnutahilis, Tulipa sylvestris, Cheiranthus Cheiri, Hes- 

 peris matronalis, Matthiola incana, and many others. In these instances, 

 the stamens and pistil not being injured, the seeds may be produced as 

 in single flowers." [Multiplicate is here used to indicate flowers in which 

 the number of petals is augmented without affecting the other parts.] 



1 Vol. XXVII. pi. 1935 in order of issue (Vol. xi. pi. 993 iu copies bound in order of 

 systematic relationship). 



2 See Watson, The New Botanisfs Guide, p. 51. 

 ^ P. 114. 



