t'EE CANADIAN ENTOMOLOGIST. 147 



eye." Is the difference between the first and second of these as great as 

 that between sharp six and flat seven of the musical scale ? 



The ratios said to exist between the lengths of fore, middle and hind 

 tibiae, are expressed definitely in numbers. If we reduce the fractions to 

 common denominators in the usual way, that we may compare their 

 numerators, we find the terms so large as to be unweildy. Let us change 

 the fractions to tenths ; the resulting numbers are. for ratios of fore tibia? 

 to hind tibiae, .6}{ + , .6^3, .6 + , and .7 Y / 2 ; for middle tibiae to hind 

 tibiae, they are .8, .8)3, .8^—, .9 or 1.0 — . The entire range of variation 

 is less than o'ne and one-half tenths in the first case, less than two-tenths 

 in the second case. The difference between first and third, first series, is 

 one-fortieth ; between first and second is one-twenty-fourth. Are these 

 differences, or even the sum of them, ultimate peculiarities of structure ? 



One item remains, the venation of the wings. The first superior 

 branch of the subcostal nervure arises "in the middle of the outer two- 

 thirds of the upper border of the cell "—is there any circumlocution in 

 thi s ? — " somewhat beyond the middle of the upper border of the cell," "at 

 scarcely two-thirds the distance from the base to the apex of the cell, 1 ' " a 

 little beyond the middle of the upper border of the cell. In fractions, 



How, then, does Lycaeides differ from another, Glaucopsyche, for 

 instance ? 1. Its eyes are naked rather than delicately and sparsely pilose 

 with very short hairs. 2. It has about 32 rather than about 31 joints in 

 its antennae. 3. Its palpi are a little less than twice, rather than a little 

 more than one and a half times, as long as the eye. 4. The ratio of fore 

 tibiae to hiad tibiae is M rather than if. 5. That of middle tibiae to hind 

 tibiae is U rather than U. 6. The 1st sup. branch of subcostal nervure 

 arises at 1% rather than at A the length of the cell. Upon which of these 

 six points rests the distinction between these genera ? Will the integration 

 of all these differentials with whatever may be implied in the shades of 

 meaning between scarcely and barely, considerably and slightly, suffice to 

 make a gross sum which amounts to more than a difference in the pro- 

 portions of parts properly accounted for as specific ? Why may not these 

 find ample room and exact determination in the same genus ? Any other 

 of the six pairs which these four names would make, if taken two by two, 

 gives a series of differences of the same nature and of equal weight. The 

 discussion of any other of the tables which lie before us leads to con- 

 clusions equally forcible and equally direct. In this resuscitation of 



