Mr. Wollaston has objected to this view that "storms and hurricanes" are somewhat rare in the latitude of Madeira and the Canaries; but this little affects the question, since the _time_ allowed for such operations is so ample. If but one very violent storm happened in a century, and ten such storms recurred before a single species of insect was introduced into Madeira, that would be more than sufficient to people it, as we now find it, with a varied fauna. But he also adds the important information that the ordinary winds blow almost uninterruptedly from the north-east, so that there would be always a chance of a little stronger wind than usual bringing insect, or larva, or egg, attached to leaves or twigs. Neither Mr. Wollaston, Mr. Crotch, Mr. A. Murray, nor any other naturalist who upholds the land-connection theory, has attempted to account for the fact of the absence of so many extensive groups of insects that ought to be present, as well as of all small mammalia and reptiles. _Cape Verd Islands._--There is yet another group of Atlantic islands which is very little known, and which is usually considered to be altogether African--the Cape Verd Islands, situated between 300 and 400 miles west of Senegal, and a little to the south of the termination of the Sahara. The evidence that we possess as to the productions of these islands, shows that, like the preceding groups, they are truly oceanic, and have probably derived their fauna from the desert and the Canaries to the north-east of them rather than from the fertile and more truly {215}Ethiopian districts of Senegal and Gambia to the east. There is a mingling of the two faunas, but the preponderance seems to be undoubtedly with the Palæarctic rather than with the Ethiopian. I owe to Mr. R. B. Sharpe of the British Museum, a MS. list of the birds of these islands, twenty-three species in all. Of these eight are of wide distribution and may be neglected. Seven are undoubted Palæarctic species, viz.:--_Milvus ictinus_, _Sylvia atricapilla_, _S. conspicillata_, _Corvus corone_, _Passer salicarius_, _Certhilauda desertorum_, _Columba livia_. Three are peculiar species, but of Palæarctic genera and affinities, viz.:--_Calamoherpe brevipennis_, _Ammomanes cinctura_, and _Passer jagoensis_. Against this we have to set two West African species, _Estrilda cinerea_ and _Numida meleagris_, both of which were probably introduced by man; and three which are of Ethiopian genera and affinities, viz.:--_Halcyon erythrorhyncha_, closely allied to _H. semicærulea_ of Arabia and North-east Africa, and therefore almost Palæarctic; _Accipiter melanoleucus_; and _Pyrrhulauda nigriceps_, an Ethiopian form; but the same species occurs in the Canaries.