82 



that it is; and I suspect that future observations will 

 confirm the fact. Meanwhile, I must content myself 

 with simply advancing the subject for consideration, and 

 with recording such few examples, in support of the 

 theory, as space will permit, and which occur to me 

 almost spontaneously. 



The Madeiras would seem to inherit, as it were, a 

 more than usual control over the alary system of their 

 insect population ; for, out of about 550 species of Co- 

 leoptera which I have hitherto met with in that group, 

 nearly 200 are either altogether apterous, or else have 

 their organs of flight so imperfectly developed, that they 

 may be practically regarded as such; so that, if our 

 preceding conclusions (from the compensation-hypo- 

 thesis) be correct, we should a priori anticipate an in- 

 crease of bulk in those islands, rather than a decrease 

 of it. Unfortunately the greater number of these 200 

 representatives are now, through the submergence of the 

 once surrounding continent, endemic, so that we have 

 no means of judging whether the obsoleteness of their 

 wings is to be referred to the long action of Madeiran 

 influences*, or whether they were thus created severally 



* This is certainly rendered probable, however, from the fact that 

 a large proportion of these apterous species are members of genera 

 which are usually winged, such as Tarus, Loricera, Calathus, 

 Olisthopus, Argutor, Trechus, Hydrobius, Ephistemus, Syncalypta, 

 PhloBophagus, Tychius, Longitarsus, Chrysomela, Scymnus, Cory- 

 lophus, Helops, and Othius, whilst the knowledge that, out of 

 twenty-nine genera which I believe to be endemic in those islands, 

 six only are winged (the remaining twenty-three being apterous), 



