TUBERCULAR SWELLINGS ON THE ROOTS OF VICIA FABA. 549 
root-hair thus infected is curiously coiled and twisted at the spot whence the liypha 
takes its origin— i.e., at the point of infection—looking as if the growth of the cell- 
wall had continued after the attack, but was profoundly affected at the point of entry 
(fig. 13a). It is sufficient to germinate a Bean in ordinary garden soil for a week or 
ten days, and then place the seedling as a water-culture, to obtain such preparations 
in nearly every case, provided the very young tubercles are examined. 
It is now necessary to say a few words as to the systematic position of the above 
Fungus. The behaviour of the mycelium is so like that of some Ustilaginese 
(especially the Entorrhiza found in Juncus bufonius) that an alliance to that group 
might readily be claimed; the difficulty of determining the membrane of the hypha, 
the glistening character of the protoplasm, the course straight through the cell-walls 
and across the lumina of the cells, are all points which remind one of the Ustilaginese. 
The dilated abutments on the cell-walls I have explained as due to the extension of 
the cell-walls by growth after the perforation. 
On the other hand, there are no septa discoverable in the hyphse; nor can I detect 
anything of the nature of a true spore like the resting-spores typical for the ordinary 
Ustilaginese, unless the haustorium-like branches are to be regarded as aborted spores. 
The “yeast-like” minute corpuscles (gemmules) which are sprouted off from the short 
branches in the cells, and which then go on budding until they fill up the space, 
appear to be the only reproductive organs which exist. 
But, in view of Brefeld’s recent discoveries as to the extensive “ yeast” formation 
which goes on in the Ustilaginese,* it seems not at all improbable that this character 
may be in favour of, rather than against, the alliance of this Fungus to the 
Ustilaginese. 
In fact, 1 regard-the Fungus as one of the Ustilaginese, which has become so closely 
adapted to its life as a parasite in the roots of the Leguminosse that it has come to 
stimulate and tax its host in an exquisitely well-balanced manner, and has lost its 
needless true resting-spores because the more numerous and tiny sprouting yeast- 
cells (gemmules) are kept in the cells of the tubercle through the dry summer 
and autumn, and freed during the rotting in the soil in the winter and spring. 
Their very minuteness and numbers enable these “germs” to become as ubiqui¬ 
tous as “Bacteria” or ordinary “Yeast” forms, thus explaining the ubiquity of the 
tubercles. 
Brefeld has shown that the ordinary resting-spores of the Ustilaginese, which 
usually take a long time to germinate in pure water, will germinate much more rapidly 
in nutritive solutions, and that several species can be made to develope their promycelia 
in nutritive solutions which had hitherto been cultivated in vain. The curious fact 
comes out, however, that when thus germinating in nutritive solutions the promycelia 
go on budding off yeast-like cells, which multiply still further by budding, and thus 
extend the parasite outside the plant enormously. According to Brefeld’s discoveries, 
* Brefeld, ‘ Botanische Untersuchungen,’ Heft 5, 1883. 
