354 PROCEEDINGS OF THE ACADEMY OF [^lay, 



also described the parasitic growths on another plant, viz., Myrica 

 gale, and named it as a new species, Frankia hruncJiorstii.^ Atkinson*" 

 gave a complete and useful summary of the literature when he pub- 

 lished his paper in 1892. He described a new species of Frankia pro- 

 ducing galls on the roots of the New Jersey tea, Ceanothus americanus, 

 which he called Frankia ceanothi. The mycodomatia on Elceagnus, 

 Hippophm and Shepherdia are considered to be due to a parasite iden- 

 tical with Frankia aim occurring on the genas Alnus. We have, 

 therefore, three named species of this genus, viz., Frankia alni (Moller) 

 Atkinson occurring on four distinct genera of phanerogamous plants, 

 Frankia ceanothi Atkinson on the single genus Ceanothus, and Frankia 

 briinchorstii Moller on the genus Myrica. 



The discovery of mycodomatia on a new host, viz., Myrica cerifera, 

 has led the writer to make a careful study of the galls and the fungus 

 that produces them. The mycodomatia were discovered on waxberry 

 bushes growing on the slopes of sand dunes at Sea Side Park, N. J., 

 where they were laid bare l^y the blowing away of the sand from about 

 the plants. Originally the bushes grew out of a low dune, and as the 

 .sand drifted in about their stems adventitious roots were formed upon 

 which grew the fungous galls, or the mycodomatia. As will be shown 

 subsequently, the fungus is perennial and the growth of the m3'codo- 

 matia is an extremely slow one. This slow growth argues for the 

 stabiUty of the dune on which the bushes grew, for if the sand had been 

 constantly shifting the roots could not have been buried sufficiently 

 long to permit of the growth of the fungous galls to the size that they 

 had reached when they were uncovered. We have, therefore, a means 

 of measuring the length of life of certain sand dunes. It seems to the 

 writer that the discovery of these mycodomatia on the adventitious 

 roots of the waxberry growing in the pure sand of the New Jersey dunes 

 throws light upon the question of the importance of these mycodomatia 

 to the host plant. 



It has been shown by the experimental work of a number of observers 

 that leguminous plants will grow in pure sand after the period of star- 

 vation is passed, provided such sand be microbe-seeded, i.e., provided 

 the right kind of tubercle bacterium is present in the sand. Subse- 

 quent chemical analysis of plants thus grown has shown that nitrogen 

 over and above the amount present in the seed is found in such legu- 



^ Moller, "Beitrag zur Kenntniss der Frankia subtilis Brunchorst," Bericht 

 der deutschen hotanischen Gesellschaft, VIII, 1S90, pp. 215-224. 



1" Atkinson, George F., "The Genus Frankia in the United States," Bulletin 

 of the Torrey Botanical Club, XIX (1S92), pp. 171-177. 



