Lichenes. 65 



Gallöe, O., Danske Likeners ökologi. [Danish Lichens 

 Oecologv.] (Dansk Botanisk Tidsskrift. XXVIII. p. 285—372. 

 May, 1908.) 



This is the first work, aiming at a thorough Statement of the 

 Effect of the outer circumstances on the modus vivendi of the lichens, 

 especially the uniform appearence of all the systematically different 

 species in every limited locality, produced by the outer circumstances 

 of the same place. The author gives much excellent Information as 

 to the subject in question, and the text is illustrated by 14 tables 

 with more than 200 figures. Special attention is, however, paid 

 to observations in nature, and, although a list of 120 books gives 

 evidence that the author has taken much trouble in stud3äng the 

 concerning literature, he states that the information, he has been 

 able to get from this, was almost useless to him except a few scat- 

 tered remarks by Lotsy, Kihlmann, Warming, Kolderup 

 Rosen vinge, Bruce Fink and Mentz. 



In the first chapter the author discusses the general effect of 

 water and light on the lichens, maintaining that the difiference of 

 seasons only slightly affect the lichens, at any rate as far as concerns 

 their vegetative activity. In the following 5 chapters the author 

 discusses the different sorts of growing places, where the lichens 

 are to be found, viz: downs, heaths, moors, woods and stones. 



The sands on the sea want lichens, most likely on account of 

 its content of salt. The new dunes have only very few lichens, 

 belonging to a limited number of species; the}^ are often covered 

 by the flowing sand; Cornicularia aculeata is always the pioneer, 

 afterwards Cladonia rangiferina and Cladonia uncialis appear. On the 

 contrary the grascovered downs are more richly supplied with lichens 

 in the naked places among the Weingaertneria. Moist sand)'' soil has 

 only ope species: Peltigera canina. The lichens, growing in unshel- 

 tered soil must be able to stand dryness, intensive light and the 

 flowing sand. They have 2 quite different ways to protect them- 

 selves against the intensive light, most of them get sunburnt (the 

 negro-type) i. c. a brown pigment is develloped in the cortex, by 

 means of which the light is caught and the interior is protected. 

 Other species get as white as chalk; so the sunbeams are thrown 

 back. When the white colour has been produced because the inter- 

 vals of the cells by the drying-process have been tiUed with air, this 

 air has the effect of a calm room, preventing the heat from further 

 Penetration and at the same time they spread the rays. In this con- 

 nection the author compares the amply develloped frame of the 

 Cladoniae, growing in the downs to the just amply developed frame 

 of the Psanima arenaria, also growing in the downs. It is supposed 

 by the author, that in both plants the frame is strongly built not 

 only to strenghten the plant, but also most likely to prevent too 

 quick evaporation from the cells to their intervals. As protection 

 against the flowing sand Stereocaulon paschale and Cladonia pyxidata 

 devellop a huge System of radiating rootlike fibres with verticaly 

 upturned side-fibres; this way of propagation of these 2 species has 

 never been recorded before. Cladonia coccifera has Hyphefibres ser- 

 ving as roots and Cornicularia aculeata, Cladonia uncialis and Clad. 

 rangiferina have a sort of graspers, formed by the bending down of 

 the branches next to the ground and dissolving them into Single 

 Hyphes. clinging to the grains of sand. The author separately dis- 

 cusses the 17 lichens, growing in sand, according to their oecology, 

 and in the same way he discusses each of the 14 epiphj'tic lichens. 



Botan. Centralblatt. Band 111. 1909. 5 



