X Journal of Agricultural Research voi. xiii 



Page 

 Plate 52. A. — Sweet potatoes showing the typical pox spots and cracking 

 previous to the falling out of affected tissue. B. — Top row: Sweet potatoes 

 showing the large pits formed as a result of a heavy infection, and later by 

 the falling out of the pox spots. Bottom row: Sweet potatoes showing the 

 constricted effect and uneven gro\vth of the root as a result of early infection . 450 



Relation op the Density of Cell Sap to Winter Hardiness in Small 



Grains 



Plate 53. Effect of wilting on ability of small grains to survive low tempera- 

 tures: Flask I. — Exposed to air for 2. 5 hours previous to freezing. Flask2. — 

 Exposed to air for 1.5 hotu-s previous to freezing. Flask 3. — Exposed to air 

 for I hour previous to freezing. Flask 4. — Exposed to air for 0.5 hour pre 

 vious to freezing. Flask 5. — Not exposed to the air previous to freezing. 

 Flask 6. — Exposed to the air for 2.5 hours, but not frozen 506 



A New Bacterial Disease op Gipsy-Moth Caterpillars 



Plate 54. A. — Photomicrograph of normal and early pathological gipsy-moth 

 muscle tissue. B. — Photomicrograph of late pathological gipsy- moth mus- 

 cle tissue showing separation of fibrillse. C. — Photomicrograph of last stage 

 in pathology of gipsy- moth muscle tissue, showing complete disintegration . 522 



Inoculation Experiments with Species op Coccomyces from Stone 



Fruits 



Plate 55. Prunus leaves from inoculation experiments, illustrating various 

 degrees of infection, as recorded in Tables I to IX: A. — P. mahaleb, infected 

 by a strain of Coccomyces from P. seroiina. B. — Pserotina, infected by a 

 strain from P. seroiina. C. — P. serasus, infected by a strain from P. avium. 

 D. — P. pennsylvanica, infected by a strain from P. pennsylvanica 569 



Plate 56. Prunus leaves from inoculation series 104 (Table II), infected by 

 strains of Coccomyces from P. cerasus: A. — P. cerasifera, infected after pro- 

 longed incubation in the greenhouse. B. — P. insititia, infected after pro- 

 longed incubation in the greenhouse. C. — P. mahaleb. D. — P. munson- 

 iana, inoculated with nattu-ally discharged ascospores on June 2 ; the in- 

 fection appeared after prolonged incubation in the greenhouse. E. — P. 

 domestica. Spots developed after prolonged incubation in the greenhouse, 

 but the fungus failed to fructify 569 



Plate 57. Plum leaves from inoculation series 103 (Table VI): A. — P. domes- 

 tica. B. — P. insititia. C. — P. domestica, uninoculated. D. — P. americana. 

 E. — P. salicina 569 



Plate 58. Prunus leaves from inoculation experiments (Table VIII): A. — 

 P. serotina, infected by a strain of Coccomyces from P. serotina, series 3. 

 B'. — P. mahaleb, sparsely infected by a strain from P. serotina, series 3. C. — 

 P. insititia, infected, after prolonged incubation in the greenhouse, by a 

 strain from P. serotina, series 105. D. — P. serotina, uninoculated, series 



105 569 



Plate 59. Prunus leaves from inoculation experiments: A. — P. cerasus, in- 

 fected by a strain from P. cerasus. B. — P. cerasus, uninoculated. C. — 

 P. pennsylvanica, infected by naturally discharged ascospores from a leaf of 

 P. pennsylvanica. D. — P. cerasus, infected by natually discharged asco- 

 spores from a leaf of P. cerasus. E. — P. virginiana, infected by a strain from 

 P. virginiana 569 



