. Cyclopedia of farm crops : a popular survey of crops and crop-making methods in the United States and Canada. Agriculture -- Canada; Agriculture -- United States; Farm produce -- Canada; Farm produce -- United States. Fig. 589. Root nodules of alfalfa 'Clustered on smaU side root- lets in this case;. Two-thirds natural size. teria. which enter through root-hairs and stimulate the of the root to the production of an abnormal rootlet, which is called the tubercle or nodule. The organism enters near the tip of the root- hair and stimulates the latter to curl into the form of a shepherd
. Cyclopedia of farm crops : a popular survey of crops and crop-making methods in the United States and Canada. Agriculture -- Canada; Agriculture -- United States; Farm produce -- Canada; Farm produce -- United States. Fig. 589. Root nodules of alfalfa 'Clustered on smaU side root- lets in this case;. Two-thirds natural size. teria. which enter through root-hairs and stimulate the of the root to the production of an abnormal rootlet, which is called the tubercle or nodule. The organism enters near the tip of the root- hair and stimulates the latter to curl into the form of a shepherd's crook. It travels down the interior of the root-hair in the form of a homogeneous strand, as seen in fresh preparations. In sections of young galls this strand is seen branched through the tissues from its point of entrance from the root-hair. These strands pass through the cell- walls by minute perforations and then enlarge again in the cell-lumen. Often the strand swells into a large body in the cell, with irregular pro- jections, which led some to think that the bacteria- like bodies found in abun- dance at a later stage were budded off from these swel- lings. These strands present in the young tubercles led a number of students to be- lieve in the fungous nature of the organism, perhaps related to the smuts; but especially by some it was considered to be one of the slime-molds similar to the Plasmodiophora brassicw, which causes the "clubfoot" of turnip, cabbage, radish and certain other crucif- erous plants. For this rea- son Schroeter, a German botanist, named it Phytom- yxa leguminosarum, and this seems to be the earliest sci- entific name. More recent investigations seem to show that the organism is one of the bacteria. Many bacteria form gelatinous masses of individuals, which take on various shapes often char- acteristic of the species. Especially on cultures on solidified artificial media are these colonies of various shapes very characteristic. These ge
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