1902.] NATURAL SCIENCES OF PHILADELPHIA. 465 



the abuonnal formation of the coi-k, until on one side of the stem 

 the barky x-idge is one-half inch high, the groove being correspond- 

 ingly deep. These ridges of bark covered with small lichens give 

 to the swelling an extremely rough, cancer-like appearance (fig. 5). 

 The wood assumes a brownish aspect and the annual rings, as seen 

 by the naked eye, are more or less wavy. Occasionally the mal- 

 formation appears as an enlarged excrescence. It would seem that 

 this excrescence began its growth upon a young lateral branch, 

 which afterward ceased its elongation and was covered up by the 

 enlarging fungus-infested mass of wood. The burls are about three 

 inches long and about two inches wide, with the bark fissured into 

 deep grooves with rather broad corky flakes. The wood to the 

 naked eye resembles in appearance the well-known curly or bird's- 

 eye maple. In another specimen examined, the swelling seven 

 inches long involves the main stem and one of its branches, so that 

 the swelling, which is fissured in the characteristic way and two 

 inches in diameter, may be said to have forked. 



The swellings produced by Gyvinosporangium Ellisii Berk, are 

 confined to the smaller twigs and branches. Near the summit of 

 young Avhite cedar trees where the branches grow upward, and are 

 thus more or less crowded together, all of these branches may be 

 involved (tig. 8). The result is the formation of fan-shaped mass 

 of swellings, which assume a fasciculate character when closely 

 crowded. The trees attacked by it may, therefore, be recognized, 

 even at a considerable distance by the peculiar distortions, which 

 consist in a dense fasciculation of the smaller branches in different 

 parts of the tree, so that, viewed from a distance, one sees closely 

 branching tufts of a corymbose outline, which appear to terminate 

 some of the branches (fig. 8). On one lateral branch of white 

 cedar, one-half inch in diameter, twelve smaller branches were all 

 massed together into a witches' broom. The external appoaiance 

 of the bark on these branches is somewhat different from tliat 

 described for G. biseptatum. Here the bark is fissured transversely. 

 With a few longitudinally directed cracks the reddish-brown bark 

 is thus divided into a numl)er of plates, rectangular in shape 

 (fig. 8). The smaller t^vigs are not thus affected, but instead have 

 a somewhat rugose continuous surface. One or two of the branches 

 involved by the fungus are dead. The swellings differ also from 

 those formed by the preceding fungal species in tapering gradually 



