July 2-Sept. 24, 191 7 



Illustrations ix 



Page 



Two New Cambium Miners (Diptera) 



Plate 48. A.—Agromyzaaceris: Larva, o, Cephalopharyngeal skeleton; 6, pos- 

 terior spiracle. B. — Agromyza aceris: Pupa. C. — Agromyza amelanchieris: 

 Larva, c, Cephalopharyngeal skeleton; d, posterior spiracle. D.— Agro- 

 myza amelanchieris: Pupa 3^8 



Toughness of Bituminous Aggregates 



Plate 49. A.— Sand. B.— Diabase. C— Biotite schist. D.— Quartzote. 



E.— Biotite granite. F. — Biotite gneiss 2>Z° 



Plate 50. A.— Altered diabase porphyry. B.— Feldspathic sandstone. C— 

 Open-hearth slag. D.— Feldspathic quartzite. E.— Chlorite schist. F.— 

 Limestone 33° 



The Cyclamen Mite 



Plate 51. A.— A healthy, a somewhat infested, and a badly infested cycla- 

 men plant with the characteristic distortion, dwarfing, and curling of the 

 foliage. B.— Flats in a greenhouse containing young cyclamen plants 

 just transferred from seeds flats into small pots, showing the proper size 

 at the time of the first spraying 390 



Plate 52. A.— Cyclamen leaves showing the distortion to the leaves due to 

 the attacks of the cyclamen mite. B.— Cyclamen flowers showing the 

 streaked parts due to attacks of the mites. C— A large cyclamen leaf, 

 showing the curling and galling effect due to the mites, and young flower 

 buds into the innermost parts of which the mites enter, resulting in the 

 streaked flowers sho\vn in figure B. D.— Young cyclamen leaves with 

 the peculiar curling due to attacks of the mites, together with an older 

 leaf with a slight curling at the lobes caused by mite attacks while the 

 leaf was young. E.— A group of eggs of the cyclamen mite 39° 



Biologic Forms of Puccinia graminis on Cereals and Grasses 

 Plate 53. Puccinia graminis tritici on wheat, barley, rye and oats 11 days 



after inoculation 49° 



Plate 54. Puccinia graminis tritici compacti on wheat, barley, rye, and oats 



10 days after inoculation ■ 49° 



Plate 55. A.— Puccinia graminis tritici compacti on Triticum vulgare, barley, 

 and Triticum compacttim— that is on common wheat, barley, and club 

 wheat. B.— Puccinia graminis tritici on Triticum vulgare barley and 

 Triticum compactum— that is, on common wheat, barley, and club wheat. . 496 



Plate 56. Puccinia graminis secalis on wheat, barley, rye, and oats 496 



Plate 57. Puccinia graminis avenae on wheat, barley, rye, and oats 49^ 



Plate 58. Puccinia graminis phhipratensis on wheat, barley, rye, oats, and 



Phleum pratense _" 49 



Plate 59. Puccinia graminis agrostis on wheat, barley, rye, oats, and Agrostis 



alba 496 



A Nursery Blight of Cedars 

 Plate 60. A.— A 2-year-old seedling of Juniperus virginiana gromng under 

 field conditions, typically affected by red-cedar blight. B.— Thuja 

 orientalis: a, inoculated at wounds in outer cortex with single spore cul- 

 tures of Phoma sp. ; b, control ; 54 



Plate 61. Spore horns of Phoma sp. upon Juniperus virginiana resulting from 



inoculation with single spore cultures under greenhouse conditions 54© 



4601°— 18 2 



