792 THE DISTRIBUTION OF SPECIES BY OFFSHOOTS. 



in consequence dried up above the stones; that this is not so may be readily proved 

 by digging, and this shows us at the same time that the humus and roots in these 

 places are quite riddled and wrapped round by the mycelium of the Fungi named. 

 The brown and grey ring- and crescent-shaped stripes show up most clearly on 

 meadows because a parallel stripe of a specially vivid green is usually seen close to 

 them. The reason of this is that, after two years, new plants develop in all those 

 places which were formerly occupied by the mycelium, and have been abandoned 

 by it in its centrifugal gi-owth. Strangely enough, these plants are not the same 

 species which were killed there in the previous year, but are herbs and grasses 

 which find a suitable nourishing soil in the places which have lain waste for 1-2 

 years. The roots and root-stocks of the plants killed by the mycelium have mean- 

 while decomposed, together with the remains of the mycelium and the receptacles of 

 the Fungi. The soil is thus manured, and plants which usually settle on fallow 

 ground grow there in abundance. They raise luxuriant stems and leaves, and thus 

 is produced on the inner side of each bare stripe a parallel one of a bright green 

 colour. 



This phenomenon has long been noticed by country people, particularly in 

 regions where pastures are an important feature. It is associated with the 

 influence of ghosts, witches, and elves; hence the name of fairy rings. In Upper 

 Austria these bai-e dry spots are regarded as the rendezvous of the witches, and 

 Walpurgis Night (1st May) is supposed to be the time when they are produced. In 

 the Tyrol and other primitive countries the most varied superstitions are held to 

 account for these curious stripes and patches. 



Fairy rings are sometimes formed by plants with underground rhizomes and 

 runners, although not so frequently as by the subterranean mycelia of the Fungi 

 named. Some Composites (for example Petasites niveus and P. officinalis, 

 Arnica Chamissonis, Achillea Millefolium), Labiates {Betonica grandiflora, Mentha 

 alpigena), Irises {Iris arenaria and I. Pallasii), Grasses, Sedges, and Rushes 

 (Hierochloa borealis, Sesleria caerulea, Carex Schreheri, Juncus trifidus), under 

 suitable conditions of soil form ring-shaped and garland-like colonies independently 

 of Fungi. The mode of growth in these plants is like that of the Dry-rot. Young 

 plants grow up with closely crowded shoots; these then spread out on all sides, and 

 the connecting links die off simultaneously. In this way the original settlement is 

 left a bare patch with dried remains surrounded by a circle of distinct and vigorous 

 offshoots. Though shoots are very numerous they still stand close together even 

 after they have severed connection, and if their annual growth is but slight it is 

 some time before an actual ring is formed. It is in this case, however, the more 

 striking, so that even a casual passer-by cannot fail to notice it. This happens 

 principally in the above-named Grass-like plants, and among them especially in 

 Sesleria caerulea, which has attained a certain celebrity in Sweden as the ring- 

 forming plant. It is there popularly termed elf dansar, and legend has it that the 

 elves are especially fond of holding their nightly dances on places where rings of 

 this Grass have been formed. 



