2 JOURNAL OF THE [January, 



apparently as luxuriant fifteen feet above, as at the base. Different 

 species of trees seem to be more or less favorable to its growth, 

 and often the shade of a limb protects it from the rays of the 

 sun and the beating rain. On the European Beech {Fagus 

 sylvatica) it is abundant at the base of the tree only ; at the 

 height of two feet, .little is found. The bark, being of a hard, 

 close texture, does not favor its growth. On the Red Maple 

 {^Acer riibntni) it does not seem to be abundant. The bark, al- 

 though rather soft, is not hygroscopic, and therefore does not 

 favor its development. On the American Elm ( Ulmus 

 Americana) the growth is most luxuriant, extending to a great 

 height, the soft spongy bark being favorable to it. On the 

 Scotch Pine {Finus sylvestris) the growth is apparently very 

 feeble, and under the microscope the cells were seen to be scarce 

 and in small detached clusters of from four to six. The outside of 

 this bark is of a corky nature and apparently not hygroscopic. 

 The color is very dark, with patches of a whitish substance, 

 which under the microscope was found to be covered with a 

 minute lichen thallus of extreme delicacy and beauty, having a 

 concave surface and finely fringed edges ; with this growth 

 but few Frotococci were found, the thallus of this minute lichen 

 contesting with them the right of occupancy. On the Norway 

 Spruce {^Abies excelsd) the growth seems to be most luxuriant 

 on the branches and upper portions of the tree, the lower part of 

 the trunk being too dry. 



In many specimens examined the gelatinous substance seemed 

 to be of sufficient consistency to hold the smaller particles of 

 quartz and foreign matter ; in many cases the uplifting mass of 

 growth was seen to carry upon it a great number of these par- 

 ticles. On the Tulip Tree {Liriodendron tulipifera) the growth 

 was the most luxuriant of any examined and the foreign matter 

 was less abundant, probably because the rapid growth standing 

 out in large projecting clusters had covered it. On the Catalpa 

 {Catalpa bignonioides) the plant had apparently been vigorous, 

 yet when examined under the microscope it was found to be of 

 a dark green, and not of that bright yellow green so characteris- 

 tic of vigorous growth. 



On the European Larch {Lartx Eiiropiea), the growth was not 

 vigorous on the trunk, while on the branches and upper portions 



