AiiMrcRY. 179 



remember that each is composed of unlike units which struggle among 

 themselves, and that, by intrasclection, the struggle ends in the pre- 

 ference of the best, i.<\, of the most useful to the organism, 



We have now reached that point at which, in spite of some of the 

 earlier statements of the learned Professor, we come to the same con- 

 clusion, viz., that internal forces originate all the variations, which 

 give rise to various modifications, whilst the particular line they will 

 follow is determined by their utility to the species. We can under- 

 stand, too, that the variational units may be absolutely undefined in 

 extent, in one case a scale, in another, the whole wing, according to 

 the needs of the case. 



This being so, we find no difficulty in agreeing that, " in the case 

 of the butterfly it rests entirely with utility to decide the size and 

 shape of the spots that shall vary simultaneously in the same direction. 

 At one time, the whole under surface of the wing appears as the 

 variational unit, and has the same colour ; at another, the inside half, 

 which is dark, is contrasted with the outside half, which is bright, or 

 the same contrast will exist between the anterior and posterior halves ; 

 or, finally, narrow stripes or line-shaped streaks will behave as 

 variational units, and form contrasts with manifold kinds of spots, or 

 with the broader intervals between them, with the result that the 

 picture of a leaf or of another protected species is produced." 



Thus we see that the germ substance of every scale varies indefin- 

 itely, that the particular variations can be selected by natural causes, 

 environment, etc., that the choice of selection depends upon the 

 respective degree of utility which each variation may have to the species, 

 and thus we see the harmony of the direction of the variations with the 

 requirements of the conditions of life. 



Notes on Apions and their Larvae. 



By CLAUDE MORLEY, F.E.S. 



The majority of coleopterists will probably agree with me when I 

 say that among the whole of our British beetles, there is no more 

 interesting genus than the Rhynchophorous one of Ajtimi. This so 

 generally expressed interest is caused rather from the similarity of form, 

 structure and habits, than is the interest in Chrij.sotuela or CeuthorlujncJms, 

 also great favourites, the species of which are so diverse in their 

 itiodns rirrnili, that one rarely finds more than two kinds in one 

 situation or upon one plant. Apiou is one of the most extensive genera 

 we have in Britain, the most extensive, in fact, with the exception only 

 of Jlomalota, and comprises 77 species, all bearing so strong a " family 

 likeness " in superficial facies, that they are scarcely likely to be 

 ascribed to any other genus (unless it be Xandphycx, to which Apion 

 vcrnalc very nearly approaches to the casual observer, and which some 

 writers consider of nearer affinity to Apian than to Ciomi.s, where it 

 is now placed), when one once has an idea of one or more of the 

 members. Upon the face of it, it would seem that 77 beetles, all so 

 much alike that their genus cannot be doubted, even by the novice, 

 must be extremely difficult to distinguish inter sc, and in one group 

 of a dozen species, this certainly is so. This is known to (and 

 execrated by) coleopterists as "the red-legged group," and itj is 



