284 THE kntomologist's record. 



their behaviour in confinement, and concludes : — "1 see no reason at 

 the present time for considering T. crepuacularia and T. biundidaiia 

 other than distinct species." Mr. Harrison, who appeared to know 

 only T. hiundularia, and the second brood of T. crepuseularia, a,nd who, 

 to square dates, assumed an allowance of a month later for the times of 

 appearance in Yorkshire, compared with our southern counties, con- 

 sidered them to be one species. A full criticism of Mr. Harrison's 

 note appeared in the Kntom., xix., p. 184. The Rev. G. A. Smallwood 

 maintained that Newman and Stainton gave him no help, and qiiotes 

 a series of letters from Doubleday to Hellins. Under date of October 

 20th, 1861, Doubleday writes: — "The dark Tephrumi is far more 

 difficult to procure than the pale one, being very local in this country," 

 the reference to the " dark " species evidently (from the next quotation) 

 refers only to the more ochreous cn'/niscnlaria, which is, in its typical 

 forms, darker than bmndidaria, and not to the melanic aberrations with 

 which we are now familiar. On February 5th, 1863, he further 

 writes: — "There is still a mystery about them. I am firmly of 

 opinion we have two species in Britain. Here (Epping) we have 

 nothing but bituididaria, they never have the ferruginous tint of 

 crepiiscidaria. About Warrington biundidaria occurs, but they get a 

 dark smoky variety, totally unlike the Scotch cirjutsrularia. In the 

 New Forest, Birch wood, etc., both species occur, but rrcjiusrulurin is 

 always out three weeks or a month before biimdul'iri'i," whilst on 

 February 23rd, 1863, he adds :— " I have always considered the 

 peculiar rusty freckling as one of the most striking characteristics of 

 crt'puscmlaria, which seems to be a very local species in this country " 

 {Ibid, pp. 161-162). 



Mr. Smallwood, commenting on these notes, shows distinctly that 

 the difference between the ' ' one species ' ' believers and the ' • two species ' ' 

 believers is purely a matter of definition, for he writes : "I can see a 

 difference between the double-brooded crepiiscidaria and the single- 

 brooded biundidaria," and then goes on to diagnose the imagines and 

 larvae from his point of view, concluding: — "But we Avant more 

 definite difterences than these, and they will, I think, be found in the 

 egg state, if at all." What is this, if it be not a matter of definition ? 

 If an individual will only tell us exactly how much or how little he 

 requires to constitute a species, we will tell him whether, under the 

 conditions laid down, we consider crepiiscidaria and biundidaria one or 

 two species. Probably the " one species " man is still a believer in 

 the immutability of species, and requires a difterence equal to that 

 which separates an ox from a hors(>, before we may label them species. 

 At any rate, there appears to be little advantage in discussing a 

 question where the non-contents will not define the position they 

 assmne. They cannot, however, get away from facts. It is proved 

 up to the hilt that T. crepiiscidaria and T. biundidaria have 

 distinct life-cycles. It is further certain that there are dozens of 

 lepidopterists who can discriminate between them in the imago state. 

 There are certain broad distinctions between the larvae. The non- 

 contents acknowledge this, but they say :--" This is not sufficient for 

 us to recognise them as two species," We ask, what would be 

 sufficient, in other words we say, " Define your term ' species ' ? " 

 This has proved, so far, too difficult for them, and we would ask 

 whether there is any advantage in prosecuting such an unprofitable 

 subject any further. 



