232 The Botanical Gazette. 
(ome 
Recent period of investigation. 
Ward** by a very careful series of inoculations with soil 
material proves conclusively that the tubercles are caused by 
some organism which is very abundant in the soil. Frank’? — 
had even earlier carried out similar experiments’ which — 
pointed to like results. Ward traces the development of the — 
fungus strands from infection in the root hairs, its growth — 
down into the cortical parenchyma, and into the tissue of the 
tubercle, where it branches in all directions. He describes 4 
and figures the peculiar enlargements where the hyphae pass — 
through the cell walls, and also enlarged portions of the — 
hyphe within the cell lumen, characters which we have set 
with the development of the sporids from the promyce 
some of the Ustilaginez, and the successive buddings of 
. Brefeld,*° Ward” : 
m. with its 
through 
consequently they had ceased to be produced 
same time the cultural researches of Hellriegel 
5®On the tubercular swellings on the roots of Vicia Faba. = 
Royal Society. crxxvim (1887). 139-562. 
°*Bot. Zeitung, xxxvir, n. 24-25, 1879. a 
_ ®°Botanische Untersuchungen. v. Die Brandpilze 1 1883. with 
©?See also, On the tubercles on the roots of Le erpegge <° 1889. 
reference to the pea and bean oceed. pager Tagedlat 
**Welche Stickstoffquellen stehen den Pflanzen 2U 
Naturf. Versamml. z in, 1886, p. 290. 
