194 Salmon . — On Oidiopsis taurica (Ldv.), 
The discovery of the existence of an endophytic member of the 
Erysiphaceae leads us naturally to ask the question whether the fact will 
have any bearing on the subject of the phylogeny of the group. If we 
find reason to believe that the endophytism is a primitive character, then 
we may seek relationship for the conidial stage of O. taurica with the 
genera Ovidaria and Ramularia . In species of these two genera, the 
conidiophores emerge through the stomata in bundles from an endophytic 
mycelium just as in Oidiopsis ; we find, too, in certain species of Ovidaria 
and Ramidaria a vague branching of the conidiophore and laterally borne 
conidia (cf. Fig. 2). On certain of its host-plants (e. g. on Asclepias ) 
O. taurica causes, as a result of its parasitism, discoloured spots on the 
surface of the leaf which are limited by the midrib and its branches ; the 
same habit, it may be noted, is found in species of Ovidaria and Ramularia. 
On the other hand, we may find reason to believe that the endophytism of 
O. taurica is not a primitive character, but one acquired by the species to 
meet certain special conditions, and that it bears no phylogenetic signifi- 
cance. Valuable evidence bearing on the point will probably be obtained 
when the entire process of the germination of the conidium and ascospore 
of O. taurica , and the first establishment of the endophytic mycelium, have 
been thoroughly investigated. 
Some remarks may here be made on the distribution and habitats of 
O. taurica . From the recorded distribution the species is seen to be 
a lover of warm or dry localities, being found most commonly in the hot 
dry countries of Central Asia, such as Turkestan, Persia, India, Syria, and 
Turkey. The species occurs also frequently in South Russia and the Crimea, 
Bulgaria, Greece, Italy, and Sicily, and has been likewise found in France, 
Spain, Germany, Hungary, and Algeria. The occurrence of the species in 
America (California) is noted below. The distribution of the plant shows 
on the whole that the species is peculiarly fitted to exist under xerophytic 
conditions. In Turkestan (Seravschan), at a height of 6,000 feet, 
O. taurica is found abundantly — occurring up to 4-5,000 feet on almost 
all the plants of the steppes. The species is reported as being abundant, 
also, about the central part of Karakoum, Central Asia. In India it has 
been collected between Lama Yara and the Phatu Pass, where it must be 
exposed to very dry winds. Indian specimens, collected by Mr. J. F. Duthie, 
were found growing on Hedysarum Falconeri under practically desert 
conditions. Examples (now in the Kew Herbarium) growing on Zygophyllum 
Fabago were collected by Dr. O. Stapf at Ispahan, in Persia, where 
a xerophytic desert or desert-steppe type of flora exists. The species 
occurs also commonly on plants growing in the deserts of Syria, Kurdistan, 
Palestine, &c. 
It seems very possible that O. taurica , by acquiring or retaining the 
endophytic mode of life, has been enabled to grow in dry, hot countries, the 
