462 PKOCEEDINGS OF THE ACADEMY OF [^^^ay, 



Berkeley- as Podisoma Ellisii. Farlow* tiausfenecl the species to 

 the geuus Gymnosporangium, and gave somewliat in detail the ex- 

 ternal appearance of .the witches' brooms caused by the growth of 

 the fungas. It causes a fasciatiou of the smaller branches of the 

 white cedar, which become more or less fan-shaped brooms. The 

 external portion' of the fungus is smaller and less gelatinous than 

 in any other species of the genus. Sargent, in the Silva of North 

 America, enumerates in a footnote (X, p. 100) the more important 

 fungi that live on the true cedars, mentioning Gymnosporangium 

 Ellisii (Berk.) Farlow and the following parasitic plant, G. blsep- 

 iatum Ellis, as of most importance from a pathological standpoint. 



HiSTOKICAL. 



The fungus Gymnosporangmm bi&eptatum was first described by 

 Ellis* in the following words: " On branches of white cedar. 

 Appearing in April, bursting through the epidermis in little 

 reddish chestnut- colored velvet-like patches which, about the middle 

 of May, pass into the tremelloid state, swelling out into gelatinous 

 masses the size of large peas ; not so distinctly foliaceous as in 

 G. junipieri. Spores long pedicellate, mostly biseptatc." Ellis, 

 also in this place, referred to the appearance of the swellings pro- 

 duced by the fungus. Farlow^ studied and described the fungus in 

 a more thorough manner, but his account has largely to do with 

 the botanical characters of the plant, the external appearance of 

 the swellings and the variation of the spores. He referred in a 

 casual manner to the fact that " the mycelium is found principally 

 in the region of the cambium." Sorauer" described somewhat 

 carefully in detail the life-liistox'y of the Gymnosporaugia and their 

 corresponding Roestelia. As the basis of his remarks, he look 

 Gymnosporangmm fuscum and Roestelia cancellata, described the 

 botanical characters of both the teleutosporic stage and the ajcidio- 

 sporic stage, and referred briefly to the other common species of the 

 genus, viz., Gymnosporangium clavaricvforme, G. conicum, G. mac- 

 ropus, G. hiseptatum, G. tr&nelloides, G. Ellisii. Wornle' inves- 



" Berkeley, Orevillca, III, p. 56. 



'Farlow, Bulletin Bussey Institute, 11, p. 22G : The Gymuosponuigiii 

 or Cedur Apples of the United States, 1880. 



* Ellis, Bulletin Torrey Botanical Club, 1874, V, p. 40. 



* Farlow, The Gymuosporaugia, etc., ])p. 19-20. 

 «SoR\UKR, Pfiamenkrankhtiten, 188'j, II, jip. 233-239, taf. X. 



' WoRNLE. Aiiatomische Untersuchung der durch Gymnosporangiou- 

 Arten hervorgerufeneu Missbilduugeu. " Inaugural Dissertation." Bot- 

 aniscJiea Centralhlatt, 1894, LX, pj). 280-2S3. 



