82 Siidifoi .appearance ami Constancy. 



out ligulate florets. From these plants I only harvested 

 the poorest possible seed on the latest branches after 

 cutting away tlie main stem and the stronger branches ; 

 l)ut from this seed, as before, I obtained nothing but 

 Discoidca (750 ])lants in 1899). 



Flowerheads without, or almost without, rays also 

 occasionally occur in races usually normal in this respect. 

 Examples of this have occurred in my experimental gar- 

 den in CJirysanthonuni coronavium, Coreopsis tinctoria, 

 Dahlia striata nana and others.^ 



In the first volume I cited numerous examples of 

 constant varieties- and showed'"' that many of them were 

 certainly one or two centuries old ; in fact as old, or 

 probably even older than, the cultivation of their species 

 itself. The varieties are generally as constant as the 

 wild elementary species, of which Draba %'erna and Viola 

 tricolor^ were cited as examples. Belonging to the same 

 group are the two remarkable types, which Hermann 

 MuLLER has distinguished in Iris Pseudacorus, of which 

 the one with narrow openings to the flower is adapted 

 for pollination by Rhingia, whilst the other is adapted 

 for pollination by bumble bees;'"^ Irwtn Lynch has re- 

 cently compiled a very complete and valuable list of 



' Further examples are given by Murr^ loc. cit. 



^ See p. ig6. Examples are afforded by GAiLLON-strawberries 

 (Vol. I, Fig. 7, p. 34) and by Chelidonium laciniatum (Vol. I, Fig. 

 36, p. 190). 



^ On page 183 of the first volume will be found a list of the vari- 

 eties known to Hunting (1671) and still cultivated. 



* See Vol. I, Figs. 3 and 4, pp. 22 and 23. For the constancy of 

 the elementary species of Viola tricolor see also V. B. Wittrock, 

 Viola Studier in Acta Horti Bergiani, Vol.11, No. i, 1897 (Cultures 

 extendiiig over three years). 



'^ H. MiJLLER^ Die Bcfruchtiing dcr Blumcn, p. C^. 



