Nov. is, 1920 Crownwart of Alfalfa Caused by Urophlyctis alfalfae 321 



which delimit uninucleated peripheral segments from a polynucleated 

 central sporogenous mass. A hyphal structure of limited growth devel- 

 ops from each of these segments and carries the nucleus in its expanded 

 termination, the latter constituting a young turbinate cell of the next 

 succession. At its mature stage the turbinate cell bears a branched 

 apical haustorium, the short axial element of which proliferates at its 

 tip a globose terminal expansion into which the polynucleate sporogen 

 ous mass of protoplasm migrates to produce the resting spore. This 

 is characterized by 9 to 15 branched haustoria in zonate arrangement 

 between the equator and the distal pole. 



. A solution of the thinner cell walls in proximity to the young, advancing 

 turbinate cells leads to the development of cavities in the hypertrophied 

 tissue in which the resting spores are finally found inclosed. 



The abundant development of the disease in the regions where it now 

 occurs is apparently associated with excessive moisture during the period 

 when infection is taking place. Any measures which can be taken to 

 reduce the moisture near the surface of the soil at this time should reduce 

 the disease. 



LITERATURE CITED 



(1) Arnaud, G. 



1916. LA MALADIE DES TUMEURS MARBREES DELLA LUZERNE. In JoUT. AgT. 



Prat., ann. 80, n. s. t. 29, no. 17, p. 291-292. 



(2) Bally, Walter. 



1911. cytologische studien an chytridineen. In Jahrb. Wiss. Bot. [Pring- 

 sheim], Bd. 50, Heft 2, p. 95-156, 6 fig., pi. 1-5. 



(3) Bary, A. de. 



1864. BEITRAGE ZUR MORPHOLOGIE UND PHYSIOLOGIE DER PILZE. PROTOMY- 



CES und physoderma. . . . In Abhandl. Senekenb. Naturf. Gesell., 

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(4) Busgen, M. 



1887. beiTrag zur kenntniss der cladochytrien. In Beitr. Biol. Pflanzen, 

 Bd. 4, p. 269-283, pi. 15. 



(5) Clinton, G. P. 



1902. cladochytrium alismatis. In Bot. Gaz., v. t,^, no. 1, p. 49-61, pi. 2-4. 

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(6) Cornu, Maxime. 



1883. sur quelques ustilaginEEs nouvelles ou peu connues. In Ann. 

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(7) Farlow, W. G. 



1908. notes on fungi, i. In Rhodora, v. 10, no. 109, p. 9-17. 



(8) FerdinandsEN, C, Rostrup, Sofie, and Ravn, F. K0lpin. 



1918. oversigt over landbrugsplanternes sygdomme 1 191 7. In Tidsskr. 

 Planteavl, Bd. 25, Haefte 2, p. 314-340. 



(9) Fischer, Alfred. 



1892. phycomycetes. 505 p., illus. Leipzig. (Rabenhorst, L. Kryptoga- 

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