Transactions. 1 7 



'2nd December, 1892. 



Mr Georoe F. Scott-Elliot, M.A., Vice-President, in tlio Cliair. 



Donations. — The Essex Naturalist for October, 1892 ; a list 

 of Californian Plants, made by Dr A. Da^•idson, presented 

 tlirougli Mr Fingland, Thornhill. Dr Chiiinock, Secretary of tlie 

 M'Dowall Memorial Committee, presented to the Society the 

 Minute Book of tliat Committee. 



Co>fXIUNICATIONS. 



1. The Influence of Insects on Flon-ers. 



By Mr G. F. Scott-Elliot, B.Sc, F.L.S. 



One must remember, in order to realise the influence of insects 

 on flowers, that our present Flora is the result of long-continued 

 selection and development. In primeval times tlie numljer of 

 species was extremely small, as compared with the present, and 

 those which did exist were of a simple generalised type, and 

 frequented by hordes of miscellaneous insects, none of which 

 displayed the specialised tastes and complex organs of our nine- 

 teenth century ones. A^ow the number of species, both of flowers 

 and insects, is extraordinary, and many show the widest and 

 most varied specialisations. Specialisation is, however, not by 

 any means invariably found at the present day. Thus there are 

 many flowers, like the gowan and daisy, which are common and 

 widely spread, and depend on crowds of insects of all kinds ; and 

 alongside these we also find highly specialised plants, like the fi^, 

 which depends for its very existence on one particular kind of 

 moth, and these latter highly specialised forms are comparatively 

 rare. Kow, in what way did insects exercise their influence, if 

 any 1 On this point there is so much confusion that one must go 

 to the very beginnings of the theory. Evolution is brought 

 about by variations. Flowers at the tip of the spike are yellow, 

 those just open are a bright rose red, while the older fading 

 flowers are mauve or purple. One sees, therefore, that the 

 flowers of this plant pass through the whole or nearly the whole 

 series of colours which one finds in the vegetable world. There 

 is no certainty as to the cause which produces this change of 

 colour in fiowoi'S, but there are some grounds for supposing that 



