438 Bulletin 315 



able literature so readily available pertaining to each species, and the diffi- 

 culty that arises in giving a good tenable description of some species in 

 the space allotted. On the whole it is perhaps preferable to allow the 

 reader to consult the originals, and for this reason the references are 

 inserted. 



In a consideration of the obligate saprophytes, it has been the attempt 

 of the writer to make a monograph of all those species that have been 

 thus far isolated from or found growing in the soil. To what extent this 

 has been successful, the future must tell. Probably there are a number 

 of species that have escaped attention. The nomina nuda species recorded 

 have been purposely omitted. 



The writer purports to present but very little that is new. He has 

 isolated some species that have not heretofore been isolated from the soil 

 but have nevertheless been described. A few species and varieties appear 

 to be new to science. All the figures are original and represent only those 

 species that "the writer has isolated. 



No key to the determination of all the species has been given because 

 of the little value that it would serve; however, it is hoped that the key 

 to the Mucorales may be of considerable use. This key is practically 

 taken from Lendner's " Les Mucorinees de la Suisse." The only alter- 

 ation has been in the way of additions to fit the few new species not pro- 

 vided for in that monograph. 



Facultative parasites 



Olpidiuni Brassicae Woron. Produces a damping off of cabbage seedlings. 

 Woronin, Michael. Plasmodiophora Brassicae, Urheber der Kohlpflan- 

 zenherni. Pringsh. Jahrb. 11: 556-561. ph. 31-32. 1878. 

 Olpidium Nicotianae Preiss. At first designated by the author as a new 

 species, now considered by him only a variety of 0. Brassicae. The 

 parasite, besides attacking tobacco seedlings, is also parasitic on cab- 

 bage seedlings, on the roots of Chenopodium album and Portulaca 

 oleracea. 

 Preissecker, K. Ein kleiner Beitrag zur Kenntniss des Tabakbaues im 

 Imoskaner Tabakbaugebiet. Tach. Mitt. d. k. k. osterr. Tabakregie 

 Heft I, Wien. 1905. 



Chrysophlyctis endobiotica Schilb. Produces the wart disease of the potato. 

 Giissow, H. T. A Serious Potato Disease Occurring in Newfoundland. 

 Dept. Agr., Central Expt. Farm, Ottawa, Canada. Bui. 63. 1909. 



Orton, W. A., and Field, Ethel C. Wart Disease of the Potato. U. S. 

 Dept. Agr., Bur. Plant Indus. Circ. 52: i-ii. 1910. 



Potter, M. C. A New Potato Disease. Jour. Bd. Agr. Great 

 Britain 9: 320. 1902. 



