LBPIDOPIEKA FROM SOUTH NORWAY. 63 



few exceptions, which are noted, ^ in the neighbourhood of 

 Vigelands Foss, on the Otteraa Eiver, about ten miles from 

 Christiansand, in the south of Norway, About thirteen years 

 ago I bought the Foss and some property adjoining, which has 

 necessitated three or four visits a year to the locaHty. On 

 these occasions I collected Lepidoptera when I could spare time 

 from other work. I paid little attention to butterflies, but took 

 thirty-two out of the ninety-six given by W. M. Sch^yen in his 

 list of those occurring in Norway, and saw two others, Parnassius 

 apollo, and Papilio machaon, perfect insect and larva, on Pimpi- 

 nella saxijraga. Systematic collecting would, no doubt, add 

 mauy species to those given in my list. 



It will be seen that in many cases I only took in thirteen 

 years one specimen of a species. With regard to this I may say 

 that I never omit to take more than one specimen of an insect 

 met with for the first time, knowing well that it does not follow 

 that I shall see it in the same locality again. Olethreutes schul- 

 ziana was abundant everywhere in the forest in 1907, but, except 

 in that year, I only saw one other specimen. 



I should say that individuals are scarce in very many species. 

 Caterpillars also are scarce. The leaves of deciduous trees at 

 Vigeland are mostly entire and untouched by insects. Anyone 

 familiar with the woodlands of the south of England cannot 

 fail to be struck by the perfect condition of the foliage of the 

 Vigeland trees. Bates, when collecting at Para, found " a great 

 paucity of individuals as compared with species," and, he adds, 

 "we rarely saw caterpillars," and comes to the conclusion that 

 "the increase of these creatures was checked by the close per- 

 secution of insectivorous animals," but as he also says that the 

 only kind of insect that appeared in great numbers of individuals 

 were ants and termites and certain species of social wasps, I 

 have wondered why he did not also hold ants as responsible for 

 some of the scarcity of individuals in Lepidoptera. 



At Vigeland the ant is the dominating insect. Ants exist in 

 countless myriads. I do not think it would be possible to find 

 a branch of a tree that was not travelled over by ants. Ant- 

 hills of very large size abound everywhere, and one has only to 

 see the spoils carried by the armies of ants which cross the 

 footpaths in brotid tracks everywhere to realise the destruction 

 of other orders of insects by ants. From the forester's point of 

 view these ants serve a useful purpose by keeping down insect 

 pests, and the natural reproduction of the forest at Vigeland is 

 extraordinarily good. 



There is a little cultivated land along the margin of the river ; 

 behind it on both sides is a maze of rocky hills rising up from 500 

 to 600 ft. The tops of these hills of crystalline rock have all 

 been rounded and smoothed by ice, and often now consist of bare 

 rock covered with patches of moss. The surface of this rock in 



