ME. H. W. BATES — CATALOGIJE 01? EETCINIDJE. 367 



those tliat take place in animals ; for aU the realms of Nature act 

 and react on each other. The atmosphere and the earth (with its 

 productions, animal and vegetable) are continually giving and 

 taking ; and as their actual relations to each other vary more widely 

 at different points along the equatorial belt than elsewhere on the 

 earth's surface, it is plain that what seems equilibrium is either 

 oscillation or progress in some direction. If plants were the only 

 organic existences, and there were no animals to aid in their repro- 

 duction, to feed upon them, to dispose of their dead carcasses, &c., 

 the dominant forms would doubtless be quite different from what 

 they are now. Darwin has shown by an admirable series of ob- 

 servations how necessary insect agency is to the fertilization of 

 the flowers of many plants. Hence the organs of those insects 

 and the parts of the flowers have been (and are being) continually 

 modified, or moulded, the one on the other. I can conceive that if 

 certain Orchids were henceforth entirely freed from the visits of 

 insects, their flowers, notwithstanding the apparent permanence 

 of inherited (though now useless) peculiarities, would immediately 

 tend to revert to the symmetry which no doubt they possessed 

 in the remote types. I have a good deal of evidence to show 

 that in tropical countries many peculiarities of structure in 

 the leaves and other parts of plants (prevailing through large 

 suites of species and genera) have been brought about, and are 

 still in part maintained, by the unremitting agency of insects, es- 

 pecially of Ants. These and many other matters require the fullest 

 investigation before the precise relations of the changes, in animals 

 and plants, that are taking place under our eyes can be properly 

 understood and appreciated. 



A Catalogue of Erycinidse, a Family of Diurnal Lepidoptera. 

 By H. W. Bates, Esq., F.Z.S. &c., Assist. Sec. Eoy. Geogr. 

 Soc. (Communicated by GEOEaE Btjsk, Esq., Sec. L.S.) 



[Read June 20, 1867.] 



The Family Erycinidse has increased so greatly, both in genera 

 and species, since the last time its members were passed in review 

 (by "Westwood, in Doubleday and Hewitson's ' Genera of Diurnal 

 Lepidoptera,' in 1851), that a new catalogue of its contents is 

 much required. It is my intention, in the present memoir, to 

 endeavour to supply this want, and to suggest a plan of classi- 

 fication of the genera — a work which has not hitherto been at- 



