172 CHAPTER II 



It thus seems clear that an introduction of foreign plants and lower animals in 

 ballast may have played a considerable role also on the Pacific coast of North 

 America. Apparently in the same way, the Carabid beetle Colpodes buchanani Hope 

 was introduced into Oregon from SE Asia (Malkin & Hatch, 1953) and it is per- 

 haps only surprising that countries facing the Pacific, especially on corresponding 

 latitudes of E Asia, have contributed so little to this immigration. Probably ships 

 arriving from there used to carry full load. 



Animals of a pronounced synanthropic type may of course have been carried 

 to the Pacific coast already with the earlier settlers, as exemplified by Essig 

 (1934)- 



Investigations on ballast-places in Southwestern England 



Several facts mentioned in the foregoing part of this chapter, in animal distribu- 

 tion as well as in the history of the Atlantic trade, suggest the British Isles and 

 above all the Southwest of England as the main region of departure for animals 

 which have been unintentionally introduced from Europe into North America. 

 It was therefore quite natural that I should wish to make a direct field study of 

 the insect fauna around the old ports of this region, especially on the ballast- 

 places, if these could still be located. These investigations were carried out in 1954, 

 between May 21st and June ist. On April 7th the same year I had already had the 

 opportunity of a few hours collecting on the Avon banks in Bristol. 



Most of the English ports mentioned in the old records of the Newfoundland 

 trade {vide Prowse, 1895, pp. 37, 40, 56, 81-82, &c.) are situated from Poole, 

 Dorset, in the south, along the southwestern peninsula to Bristol on the west coast, 

 the majority in Devon (map, fig. 16). I visited the following: Poole, Topsham, 

 Dartmouth, Plymouth, Bideford (Appledore), Barnstaple (incl. Fremington), and 

 Bristol. 



By means of preceding correspondence with initiate persons in every port and 

 inquiries on the spot after my arrival, I tried to find out the exact position of the 

 place where in old days sailing-vessels used to take on ballast, and in this respect, 

 thanks to most generous information from Mr. Mathews and the late Mr. Boyle, 

 both mentioned above, was especially successful at Poole and Bideford. In case 

 no exact information was available, the collecting was made as close to the oldest 

 parts of tlie port as possible, or on spots which for other reasons seemed most 

 likely to have been used as ballast-places. 



The terricolous fauna was the main object of collecting and I tried to obtain 

 complete lists of the following groups of animals: Coleoptera, Hemiptera Heteroptera; 



