Schwartz . —Parasitic Root Diseases of the Juncaceae . 519 
into hollow spherical balls in all respects similar to the sorospheres of 
S'. Veronicae. It is true that the spores of S. Junci are more frequently 
collected into ellipsoidal masses or are merely loosely aggregated and fill 
the root-cells ; this, however, is probably due to the non-hypertrophy of 
the root-cells of the host-plant, which by retaining their normal size do not 
allow sufficient room for the parasite to form its typical sorospheres. The 
cramping effect of the narrow root-cells on sorosphere formation is also 
evidenced by the presence of small soropheres consisting at times of only 
eight spores ; to the same cause may be attributed the comparative rarity 
of schizogony, which is of such frequent occurrence in the enlarged cells of 
Veronica tumours. The description of the genus ‘ Sorosphaera ’ should be 
modified so as to include S. Junci into—‘ Sporont giving rise to wedge- 
shaped spores either loosely aggregated or collected into spherical or 
ellipsoidal hollow balls, and usually enclosed by a common membrane.’ 
The present writer is in agreement with the conclusion arrived at by 
Maire and Tison in their paper relating to the affinities of the Phytomyxineae, 
to the effect that these fungi should form a distinct order intermediate 
between the Sporozoa and the Mycetozoa. They are to be distinguished 
from the latter by the form of their vegetative nuclear division, their non¬ 
cellulose spore membrane, the non-formation of plasmodia, and, lastly, by 
their parasitic mode of life. The Acrasieae differ from the other Mycetozoa 
in not forming plasmodia, and to that extent approach somewhat nearer to 
the Phytomyxineae. The Chytrideae differ in the formation of zoosporangia. 
In 1899 Schroter, in his article on the Phytomyxineae in Engler 
and Prantl’s ‘ Die Nattirlichen Pflanzenfamilien included the following 
species:— 
1. Ptasmodiophora — Brassicae, Wor.; Alni, Moll.; and Elaeagni ) Schrot. 
2. Tetramyxa parasitica (parasitic on Ruppia rostellata and Zanni- 
chellia palustris ), Goeb. 
3. Sorosphaera Veronicae , Schrot. 
4. Phytomyxa Leguminosarum , Schrot. 
From this list P. Atni , P. Elaeagni, and P. Leguminosarum have since 
been removed. The root-tubercles of the Alder and Elaeagnus , of which 
I have cut and examined many sections, show no evidence of the existence 
of any nuclear parasite, and the organisms seen in them bear only a super¬ 
ficial resemblance to a Ptasmodiophora. The root-nodules of leguminous 
plants have now been recognized as due to the symbiotic presence of 
bacteria. 
We have now to add to the list given by Schroter Tetramyxa Tri - 
glochinis, Moll., parasitic on Triglochin palustre, and also recently found on 
Triglochin maritimum by Maire and Tison, and Sorosphaera Junci , parasitic 
on various species of Juncus , found by the present writer. 
