LYC^NID^ IN NORTH KENT. 295 



to be quite equal to that between the more closely allied European 

 Argynnidse and Melitsese." In this I most decidedly agree with 

 Mr. Tutt, but then I regard some of the groups in the genera 

 Melltcea and Argynnis in exactly the same light as I do the 

 particular group of Lyccense considered in my recent notes. 



Further on Mr. Tutt asks, Why should we not call the 

 common ancestor of Lyccena icarus, Polyommatus phlcEas and 

 Thecla rubi a species, and treat all and each of its descendants as 

 varieties or aberrations ? Well, perhaps we should not be very 

 wide of the mark if we did so ; but apart from the fact that the 

 ancestral species is an unknown quantity, the interests of science 

 demand that all the descendants shall be parcelled out and 

 docketed as aberration of such and such a species, — species of 

 this genus and genus of that family. 



I cannut agree with Mr. Tutt that if an insect is not a pure 

 species it must necessarily be considered an aberration. As 

 regards classification, I contend that my use of the term " pure " 

 in a comparative sense in no way affects the status of the insects 

 under consideration. As species are usually determined I am open 

 to admit tliat icarus, bellargus and corydon are more distinct from 

 each other than are the members of certain groups of species in 

 the Tineina. The difference of opinion between Mr. Tutt and 

 myself lies principally in the value we attach to the term "species" 

 as applied to the three insects in question. If Mr. Tutt con- 

 siders these insects as pure species in the sense I have indicated 

 {ante, p. 121), then he is certainly only consistent in calling the 

 issue of a cross hybrids. I can, however, only suppose the 

 insects to be as I have previously stated, not pure species, or, in 

 other words, species which are but a step as it were above the 

 stage known as a race. In fact, I cannot see any clear line of 

 demarcation between such species as these and the domestic 

 breeds of pigeons, sheep, and dogs. Some of the breeds of 

 pigeons, for instance, have kept true for centuries, and compared 

 one with the other are manifestly more distinct than is icarus 

 from bellargus. We, however, know something definite of the 

 common origin of the domestic races of birds and mammals, and 

 so we term them "breeds"; but in the case of the butterflies under 

 consideration, although we may reasonably suppose that they have 

 all three descended from a common stock, yet we have no actual 

 knowledge of this, and we therefore dub them " species." 



