86 
other reserve materials in mid-winter (January 19, 1889), it was found 
that the diseased parts were doubly infested. The basal portion of the 
bud scales were almost cord ed over with small, nearly spherical, dark 
bodies which proved to be the perithecia of the new species of powdery 
mildew, Splicerotheca pliytoptophila, recently found in Kansas, and de¬ 
scribed by Professors Kellerman and Swingle in the September issue of 
the Journal of Mycology, page 93. At this season of the year all traces 
of the mildew are absent from anything except the infested or abnormal 
branches, and upon these the perithecia are limited to the bud scales, 
with a particular preference shown to the lower portion of the scale. 
Upon further study, the buds infested w r ere found to be much larger 
than those upon healthy branches and contained the perithecia in all 
their tissues. For example, a bud well up from the base of a twig might 
not show any signs of perithecia upon the exterior, but when the large 
loose scales were removed the bases of the inner ones would expose a 
dark covering consisting of the mildew perithecia. Longitudinal sec¬ 
tions through such buds showed that the living tissue of an ordinary 
bud was absent, and its space was occupied by an entangled mass of 
fungous fruit. 
It is quite unusual to find a powdery mildew which is so particular 
as this one in the selection of the place for bearing the perithecia, both 
as to the character of the branch it selects (an abnormal one) and the 
part upon it. As fungus parasites thrive upon compounds rich in al¬ 
buminous substances, and as the Phytoptus induces a rapid and there¬ 
fore comparatively succulent growth upon a tree that normally has a 
dense wood, firm bark, and minute, closely protected buds, it may how¬ 
ever not be so strange that the Splicerotlieca will flourish upon the 
distortions caused by the mite when it fails to gain a foothold upon a 
healthy tw ig. The extremely favorable conditions offered by the u birds’ 
nests” of soft, green, nourishing tissue, developed through irritation of 
the mite, probably have vastly more to do with the presence of the 
fungus than any lack of vital activity or so-called resisting power in 
the diseased twigs. It is in these parts that the Celtis makes much 
more rapid growth than in the normal imrts. It was, moreover, ob¬ 
served that in a cross-section of the stimulated branch there was con¬ 
siderable starch scattered through the bark, while in the healthy and 
mature twigs, where the buds were normal, smooth-coated, and var¬ 
nished, there was no starch outside the ring of firm wood. This starch 
in the bark may be the secret of the success of the Splicerotheca upon 
the infested branches, for the substance under the action of organic 
ferments yields grape sugar, a most acceptable food for parasitic fungi. 
If the powdery mildew was a deep feeder like the Peronosporas the 
conditions would be different and the nearness of food supply to the 
surface of the host of less consequence. 
