Sclavartz.—Parasitic Root Diseases of the Juncaceae . 521 
by allowing them to do so in situ in the tubercle ; if kept continuously in 
the open they germinated early in May. 
I regret that all my attempts at germinating the spores were un¬ 
successful, the more so as in the absence of germination it is impossible to 
absolutely establish the mode of infection. I kept spores in the open 
through the winter under about a quarter of an inch of water, which was 
approximately similar to their natural condition, for many of the nodules 
are found scarcely beneath the soil under a depth of about one inch of 
water ; I also found tubercles early in March which had wintered in their 
natural habitat. Spores from both these sources were sown in water and 
in various culture media containing sugar or plum-juice; temperatures 
ranging from io° C. to 25 0 C. were maintained, but in no case was any good 
germination observable, the best results being from a spore which produced 
three small hyphae, but these gave rise to no sporidia. 
Weber states that the spores produced promycelia, from the ends of 
which sporidia were abjuncted; nevertheless, he was unable to cause 
infection to healthy plants by means of the spores thus germinated. 
The result of my observations on these tubercles has been to confirm 
the conclusions arrived at by Weber, excepting as regards the spore 
germination, and to suggest the probable mode of infection by the entry of 
conidia into root-hairs. Struck by the healthy appearance of the aerial 
parts of Juncus plants whose roots may in reality bear three or four large 
tubercles, one is inclined to think that perhaps the fungus stimulates the 
plant and increases its power of absorption of food from the soil. 
In conclusion, it is interesting to note that the fruits of J. bufonius are 
at times infected by an Ustilaginous fungus, Tolyposporuim Junci ; but 
whether this is related in any way to the Entorhiza , I am not in a position 
to say, not having been successful in finding it. 
My thanks are due to my sister, Miss Alice M. Schwartz, for her 
assistance in making the drawings. 
Summary and Conclusions. 
1. The roots of Juncus bufonius , J. articulatus , and J. lamprocarpus 
are subject to the attack of two distinct parasites, viz. Sorosphaera Junci 
and Entorhiza Cypericola. 
2. The life-history of S'. Junci closely follows that of S. Veronicae , 
to which it is nearly related, the methods of nuclear division being similar. 
3. Infection by the Sorosphaera occurs by the penetration of an amoeba 
into a root-hair and thence into the root itself. 
4. The roots attacked by the Sorosphaera are not hypertrophied, 
whereas those attacked by the Entorhiza form tubercles. 
5. Infection by the Entorhiza is probably effected by the entry of 
conidia into a root-hair. 
