( Ixix ) 



I might also refer to the successful fertilisation of red 

 clover in New Zealand by the importation of impregnated 

 queens of our common humble-bee ; to the re-discovery of 

 the fact, first noticed by Francis Walker in 1848, of the 

 migrations of Aphides, or plant-lice, from one food-plant to 

 another at different stages of their development, enabling 

 them to be more successfully pursued and exterminated, 

 — another feather in the already well-decorated cap of our dis- 

 tinguished colleague Dr. Eiley, — and to the uses to which the 

 silk produced by various exotic species of Bomhycid<B, other 

 than our common silk-worm, has now been successfully 

 applied. 



Many other conspicuous instances in Economic Entomology 

 could be mentioned, if time permitted me to enlarge upon 

 this portion of the subject. 



The artificial breeding and rearing of Lepidoptera in 

 captivity must always prove a valuable auxiliary to the study 

 of the laws of heredity, protective resemblance, and natural 

 selection. The elaborate work of Weissmann, Poulton, and 

 many others has already been the means of eliciting much 

 interesting evidence on these subjects, and we may hope that 

 the time will come when organic chemistry in relation to 

 changes of colour may be so well understood that some con- 

 nection may be established between the various analogous 

 phenomena so constantly observed in different sections of the 

 animal and vegetable kingdoms. Should it ever be discovered 

 by what precise method certain spiders can adapt their tints 

 to those of the objects on which they rest, or certain larvas 

 can, as it were, partake of the colour of their food-plants, it 

 will yet remain to be shown whether the same laws affect the 

 assimilation of fishes and lizards to their surroundings ; or 

 the correspondence of autumnal leaves to the ripened fruit of 

 red and yellow gooseberries respectively ; or, as has lately 

 been suggested, the prescient arrangement of the material of 

 its nest by the red-backed shrike according to the colour of 

 the eggs to be deposited. 



Colour, in the sense in which we understand it, can surely 

 be neither infectious or contagious, but if the laws of organic 

 chemistry, which govern it, should ever come to be well 



