248 SIBERIA IN EUROPE. chap. xx. 



and lessens the production of insect-life. Many of our 

 European birds winter on both shores of the Mediterranean. 

 In wandering through the valleys of Asia Minor, or the 

 mountain-gorges of the Parnassus, or on the islands in the 

 lagoon of Missolonghi, in May and June, I noticed no 

 absence of insect-life. On the contrary, insect-life appeared 

 to be superabundant. Vegetable-life appeared to be threa- 

 tened by innumerable grasshoppers. One of the prominent 

 features of the district was the countless thousands of 

 beetles which swarmed on every plant, and, if we may judge 

 from the number and size of their webs, the countries I have 

 named must be a perfect paradise for spiders. That these 

 districts are suitable for the maintenance of insectivorous 

 birds during summer is proved by the fact that, soon after 

 the Phylloscopi, which have wintered there, have left, their 

 place is filled with birds belonging to the allied genus 

 Hypolais, so that the olive-trees are well supplied with insect- 

 eating birds both winter and summer. One species of swal- 

 low winters in Greece, one is found there all the year round, 

 and three other species are summer migrants to that country. 

 In some cases no doubt the weaker birds are turned out by 

 the stronger. Swallows arrive in Diisseldorf early in April. 

 For some weeks they circle over the town, like a swarm of 

 bees. Early in May the swifts arrive, and soon become as 

 abundant as the swallows were, whilst the latter birds are 

 rarely seen during the summer. 



Too much has probably been made of the great lines of 

 migration, the highways which lead from the summer to the 

 winter quarters. It has been asserted that there is a con- 



