The Zoologist — April, 1871. 2571 



introductory portion of the paper terminated with an examination of the 

 origin of the beetle-fauna of these islands, according to the theories of 

 Mr. Murray, as enunciated in his treatise ' On the geographical relations of 

 the chief Coleopterous Faunae,' and of Mr. Wallace, as explained in his 

 recent presidential Address. From obsei'vatious made m situ, establishing 

 a remarkably homogeneity of character in the fauna of the several groups, 

 up to a certain nucleus, and then diminishing towards the south, Mr. Wol- 

 laston adhered to his original idea of a former land-connection between the 

 groups, afterwards broken by some gigantic catastrophe; and in this 

 respect he favoured the views of Mr. Murray more than those of Mr. 

 Wallace, who contended that the insect-population had been chiefly 

 influenced by atmospheric phcsnomena, such as storms and hurricanes. He 

 remarked, in support of his opinion, that storms were of very rare occurrence 

 in that part of the Atlantic, the wind blowing as a moderate breeze almost 

 uninterruptedly from the north-east, with an occasional storm from the 

 south ; and he was willing to admit that these storms might possibly 

 account for the slight Afi'ican element in the fauna ; but the large number 

 of Mediterranean types could not, in his opinion, have originated from 

 atmospheric causes. Floating timber, and human agency, especially the 

 introduction of plants from Europe, and from one island into another, no 

 doubt played a not inconsiderable part both in the character of the fauna as 

 a whole and in its details. 



A lengthened discussion followed the reading of this paper, in which the 

 President, Mr. Bates and Mr. Murray, who was present as a visitor, took 

 part. 



Mr. Bates considered that Mr. WoUaston had adduced no new facts 

 calculated to convert those who do not believe that the present community 

 of species in these islands is to be explained by former land-connection 

 inter se and with south-western Europe. Mr. WoUaston had not endea- 

 voured to meet the objection to his theory, raised by Sir C. Lyell in his 

 ' Principles of Geology,' viz., that the Atlantic Islands, and especially the 

 Azores, are separated from the continent of Europe by a sea of from 10,000 

 to 15,000 feet in depth. It was pretty generally acknowledged that all 

 great geological changes were exti'emely slow in their operation, and this 

 being the case, a land-depression of that magnitude must have occupied a 

 length of time that could only be measured by geological epochs ; in fact, 

 would throw back the operation to a period probably prior to the origin of 

 the now existing insect fauna of the islands. It was not in accordance with 

 the present state of Science to call to our aid the idea of " great catas- 

 trophes," and if that course be adopted, we should be prepared with facts 

 in support of the theory. 



Mr. Murray agreed with Mr. Bates with regard to his remarks on " great 

 catastrophes," and thought Mr. WoUaston in that respect had chosen a 



