ILLUSTRATIONS O 



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Fig. 15. — Photo-micrograph showing a transverse section through an 



almond root with gall attached 36 



Fig. 16. — Same as Fig. 15, with the exception that the section is 

 through the center of the gall, and showing the central 

 region of the onthnrsting cambium 37 



FlG. 17. — Photo-micrograph of a section through a j-oung gall, show- 

 ing isolated woody nodules surrounded by meristematic 

 tissue in a ground tissue of large, thin-walled paren- 

 chyma. . . 38 



FlG. 18. — Photo-micrograph of isolated woody nodules from the 



surface region of a fair sized gall 39 



Fig. 19. — Diseased parenchyma cells of the young gall . 4 2 



Fig. 20. — Amoeboid, cyst-forming plasmodium. Three views of the 



same individual drawn at intervals of two minutes 43 



Fig. 2i. — Cyst-forming plasmodium drawn at intervals of one minute 43 



Fig. 22.— Cyst-forming plasmodium ; Nos. 1 and 2 drawn at intervals 

 of two hours the first day after placing in hanging drop ; 

 No. 3, the fully formed cyst of the same individual, the 

 second day after placing in hanging drop 44 



Fig. 23. — Section through the large parenchyma cells adjacent to the 

 surface of the gall, showing the large intercellular 

 spaces and the cells partially filled with finely retricu- 

 lated, rather dense masses of vacuolar protoplasm 45 



Fig. 24. — Same as Fig. 23, with the exception that the drawing 



was made an half hour later 45 



Fig. 25. — Photo-micrograph of a section through a young gall, show- 

 ing the position of certain cells with their contents 

 darkened by the action of Flemming . 47 



Fie. 26. — Multinuclear cells from the meristematic tissue of a young 



gall 51 



Fig. 27. — Seciion through the surface tissue of the gall, showing the 

 plasmodium migrating to the surface prior to fructifi- 

 cation 52 



Fie. 28. — Fragments of the capillitium with adhering spore masses. 54 



FlG. 29. — Spores, germinating spores, swarm cells, and the frag- 

 ments of the spore-membrane a few hours after germi- 

 nation 54 



FlG. 30. — Stumps of diseased trees removed from an infested orchard 



and distributed about the country for stovewood 57 



FiG. 3 1'. — Present condition of the Glendale almond orchard, the 



dead and dying trees having been recently cut down. . . 59 



Pi.aTK. — Various phases of the diseased tissue as shown in fixed 



and stained sections 48 



