Elliott: Characters of Southern Tuckahoe 227 



the appearance of the roughened bark of a large root, or, more 

 nearly, of the bark of a tree trunk or branch, and for the same 

 reason. A microscopic study of the cortex of the sclerotium may 

 show little, if any, of the original wood or bark of the host, but 

 the fungous cortex will be thicker and denser in some places than 

 in others. The old cortex evidently stretches and cracks as the 

 sclerotium enlarges, the newly developed cortex filling in the gaps 

 between the older portions, making the surface rough and uneven. 



The writer is much indebted to Mr. H. R. Rosen and Prof. E. 

 A. Burt, of the St. Louis Botanical Garden, and Miss E. B. Hawks, 

 of the United States Department of Agriculture Library, for ref- 

 erences to literature, and especially to Mr. Rosen for his interest 

 and assistance in the study. 



Arkansas Experiment Station, 

 Fayetteville, Arkansas. 



Literature Cited 



1. Berkeley, M. J. Indian Bread or Tuckahoe. The Gardener's Chronicle, 



829. 1848. 



2. Bommer, C. Sclerotia et Cordons Myceliens. 1894. 



3. Braconnet, H. Recherches sur un nouvel acide universellement repandu 



dans tous les vegetaux. Annales de chimie et de physique. 25: 35^- 

 373- 1824. 



4. Fischer, E. Beitrage zur Kenntniss exotischer Pilze. Hedwigia. 2: 61- 



126. 1891. 



5. Gore, J. H. Tuckahoe, or Indian Bread. Smithsonian Report, 687-701. 



1 88 1. 



6. Prilleaux. Le Pachyma Cocos en France. Bulletin de la societe botin- 



ique de France. 36: 433. 1889. 



7. Torrey, J. Analysis of the Sclerotium giganteum or Tuckahoe. The 



Medical Repository, new series. 6: 37~44- 1821. 



8. On the pectic acid of Braconnet, and its identity with Sclerotin, 



a peculiar principle existing in the Tuckahoe, or Indian Bread. (New 

 York Medical and Physical Journal. 6: 481-490. 1827.) 



Explanation of Plates 17 and 18 

 Fig. 1. External view of Pachyma cocos Fries, showing roughened bark- 

 like cortex. 



Fig. 2. Cut surface of Pachyma cocos after drying about 24 hours. The 

 homogenous character of the interior is evident. (The coin is a one-cent piece.) 



Fig. 3. New cortex grown on cut surface of a tuckahoe (shown in Fig. 2), 

 and remnant of rhizomorph shown in Fig. 4. 



Fig. 4. Rhizomorph produced by a tuckahoe growing on a greenhouse 

 bench. (This negative was scratched.) 



