75 
EXPLANATION OF PLATES. 
Plate XI. 
Fig. 
1. Peach leaf infested by Cercospora circumscissa, Sacc., natural size and show¬ 
ing about forty-live points of infection. The circular pieces of dead tissue 
have fallen out in several places. The leaf was taken in October from a 
tree immediately adjoining a badly infested almond tree. Orchard of J. 
S. Baldwin, Orange, Cal. 
2. Almond twig, new growth, infested by C. circumscissa, Sacc. From orchard 
of J. S. Baldwin, Orange, Cal. Natural size. 
3. Almond twig, old wood (?), magnified 2^ diameters; a, the oval disk of tis¬ 
sue killed by the fungus; b, central, lighter, eonidia-bcaring portion; c, 
the fascicles of conidiopliores; cl, d, large portion of the side of the twig, 
probably indirectly killed by the fungus. 
4. Transverse section through an almond twig partially killed by C. circum¬ 
scissa, Sacc., enlarged 16 times; a, pith cells; b, xylem and xylein rays; c, 
phloem and phloem rays; d, cortical parenchyma; e, epidermis; /, corti¬ 
cal parenchyma killed by the parasite; g, fruiting bodies of the parasite; 
li, cambium tissue and xylem rays destroyed. 
5. Almond leaf affected by the fungus, natural size. 
6. Small portion of an affected almond leaf, magnified 3J- diameters; a, disk 
affected by the fungus; b, somewhat lighter, conidia-bearing center; c, 
crescent-shaped space left by the shrinking of the infected tissue; cl and 
e, spaces where the tissue has been excised through the action of the para¬ 
site. 
7-8. Transverse section of an affected spot in an almond leaf, showing the curv¬ 
ature of the tissue and the contained and protected fruiting bodies. 
9-17. Conidia and conidiopliores, the former in various stages of growth. The 
conidium at Fig. 17 is mature and separating from its conidiophore, show, 
ing at its base a vesicular membrane or sterigma occasionally observable. 
A large number of conidiopliores of many forms, the straight, shouldered- 
curved, and more or less dentate forms are here shown. 
18-29. Various forms of mature conidia, from those of 2 cells (Fig. 26) to those of 5 
cells (Figs. 23 and 27). One bifurcate conidium is shown in Fig. 29. 
30. Section of infested almond leaf, showing the fascicle of conidiopliores rest¬ 
ing on an indistinct, tubercular base, from which arise at least two hyphm. 
The cells of the leaf are much shrunken and some of them are out of place, 
owing to the efforts made to free the mycelium from the tissue. 
Plate XII. 
Figs. 1-3. Conidia of C. circumscissa prior to germination; a, enlarged extremities of 
the spores prior to germination, and showing the clear spot seen before 
the pushing out of the germ tube. 
4. Conidium of 4 cells with newly formed germ tubes at a a. 
5-9. Conidia of 2, 4, and 5 cells, with one or more germ tubes, unbranched and 
of various lengths. Figs. 6-9, a, show the gathering of the cell contents 
at the ends of the cells and the numerous refractive bodies found there 
at the time of germination or before. 
10. Conidium of 5 cells after germination from the end cells; a, retracted con¬ 
dition of the equatorial portion of the cells just prior to germina tion. 
11. Conidium of 5 cells with 2 germ tubes; a, a germ tube arising from the 
central cell at the angle between the lateral wall and the transverse 
septum. 
