500 SUMMARY OF CURRENT RESEARCHES RELATING TO 



measuring 10 by 14 cm., was deprived of several large apothecia. Tlie 

 lobes all pointed in the same direction, and the plant increased 1 "75 cm. 

 in one year. Two other plants, deprived of their lobes, regenerated and 

 increased from 2 and 5 cm. respectively to S • 5 and 6 cm. No other 

 measurements are quite so high as these, though a plant of Parmelia 

 caperata (sterile), measuring from 1 • 2 cm. across, reached in eight years 

 a dimension of 10 by 13 cm. Other plants of the same species gave 

 much slower rates of increase. A section of railing was marked 

 bearing minute scattered squamules of Cladonia fityrea. After two 

 years the squamules had attained normal size and podetia were formed 

 2 to 4 mm. long. 



Several areas of Verrumria muralis were marked and after ten 

 months were again measured; the largest plants, measuring 2*12 by 

 2 "4 cm. across, had somewhat altered in dimensions and gave the 

 measurements 2 • 2 by 3 cm. 



A quadrate of limestone rock was scraped bare of moss and of 

 Leplogium lacerum, except for bits of the moss and particles of the 

 lichen which adhered to the rock, especially in depressions of the 

 surface. After four years the moss was colonizing many small areas, 

 and many of the patches bore specimens of the lichen 2 to 10 mm. 

 across. Very little change occurred during the next four years. 



The results as far as possible are summarized and opinions hazarded 

 as to methods of migration to denuded areas. The general rate of 

 increase is given for a varied series of lichens. Some crustose species 

 become established and produce thalli and apothecia in two to eight 

 years. Foliose lichens increase in diameter from • 3 to 3*5 cm. per 

 year (the latter observation not verified in the text). So far as external 

 appearance goes apothecia are produced in one to eight years ; it is 

 concluded that these require four to eight years to attain maturity in 

 their natural habitats. 



Mycetozoa. 

 (By A. LoEEAiN Smith, F.L.S.) 



Observations on Badhamia utricularis.* — AV. T. Elliott has been 

 experimenting with the plasmodium of Badhamia and its food supply. 

 He holds the view that Badhamia and other mycetozoa do not live 

 solely on bacteria but also on fungi, that they probably assimilate the 

 fungus mycelium so abundant in the dead wood they occupy. He 

 tested the plasmodium on a series of fleshy fungi, and he has observed 

 the partial disappearance of the fungus, and the changes in the 

 Plasmodium according to the colour of the fungus on which it was 

 feeding. Elliott looks on mycetozoa as parasites more animal than 

 vegetable ; they assimilate or consume the tissue of the living fungus^ 

 withdrawing nutrient substance, including proteids, from the host. 



* Trans. Brit. Mycol. Soc, v. (1917) pp. 410-13. 



