ZOOLOGY. 177 
could not possibly, in their present condition, have been trans- 
ported over the six hundred miles of ocean that now intervene be- 
tween these groups. Mr. Wollaston has, however, discovered that 
beetles have a tendency to become apterous in these islands; 
many which are winged in Europe, or belong to winged genera, 
being altogether wingless in Madeira and the Canaries. Some of 
these wingless species differ in no other respect from their Euro- 
pean allies, so that we may be sure the change has been effected 
in a comparatively limited time ; and the fact that some European 
Species possess both winged and wingless individuals’ shows that 
the character is an unstable one, and therefore easily abolished or 
retained as one or the other state becomes advantageous to the 
species. We are thus at liberty to suppose that these wingless 
Atlantic groups are the descendants of very remote winged an- 
cestors, who were among the earliest immigrants to all these 
islands ; and these being subjected to similar conditions, all became 
apterous. Another strange phenomenon is presented by the Elas- 
trus dolosus, a beetle of the family Elaterids which belongs to a 
genus peculiar to Madagascar. A single plant, Myrsine Africana, 
a native of tropical Africa and the Cape of Good Hope, is found 
in no other group but the Azores where it seems to be common. 
As another beetle of the same family (Elateridw) is allied to a 
Brazilian species and is therefore probably the descendant of an 
ancestor who came over in a floating log, we are led to speculate 
on the possibility of this anomalous Madagascar beetle and S. 
African plant having been introduced by a similar process ; since 
the currents round the southern extremity of Africa partially 
merge into the great equatorial current of the Atlantic which gives 
tise to the Gnif Stream, and this undoubtedly reaches the Azores. 
Mr. Godman had previously visited the Galapagos Islands, which 
are only half as far from South America as the Azores are from 
Europe, yet they contain hardly any identical species of birds, 
Plants or insects. This is well explained by the fact that these 
islands are situated in a region of calms instead of one of storms ; 
and chance introductions being therefore a far rarer occurrence, 
the early immigrants have all become modified, and have so 
Stocked the country with their peculiar and well adapted forms 
iy a new comers (if any do come) have little chance of establish- 
ng themselves. — Airrep R. Warraor, in the Academy. 
AMER. NATURALIST, VOL. VI. 1 
