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A LOG AND SOME MYCETOZOA. 



By A. E. Hilton. 



(Read March 9th, 1920.) 



In a shady corner of my garden at North Finchley is a log which 

 looks hoary with age. The bark is deeply furrowed ; some of it 

 is loose, and much is missing. The wood is rotting, and so 

 spongy in places that birds peck pieces from it, probably hunting 

 for larvae. It is the home of myriad insects, and has been the 

 abode of several kinds of Mycetozoa. 



Seven years ago it was the living trunk of a lime tree ; not, 

 I think, the small-leaved lime tree {Tilia Euwpaea) but T. 

 platyphylla, the leaves of which are broader and larger. Its 

 age, when cut down, I cannot tell. The diameter of the log is 

 about fifteen inches, but the rings at the sawn ends are too 

 obscured to be counted. It was soon attacked by fungus, chiefly 

 Polyporus, and penetration of the wood by mycelial threads 

 hastened decay, and helped to prepare a habitat for Mycetozoa. 



I first found Mycetozoa on the log in August 1915, after a 

 month or more of heavy and frequent showers, and warm tem- 

 perature (about 20° C). A crowded patch of minute sporangia 

 of Perichaena corticalis then appeared, covering about one square 

 inch. When discovered these were brown, but they afterwards 

 became grey with calcareous deposits, and in a day or two were 

 disfigured with fungus hyphae. 



My next record shows that three years later, in the middle of 

 August 1918, after a fortnight of fine and warm weather (again 

 about 20° C.) had followed a period of wet and unsettled condi- 

 tions, the appearance on the log of patches of light yellow enabled 

 me to watch the formation of aethalia of Fuligo scptica. When 

 first seen, at 4.15 p.m., the emerging plasm covered about twelve 

 square inches. It then seemed to be a thin layer gathering up into 

 small papillary sporangia, very confluent and indeterminate. 



