July i-Sept. 30,1918 
Illustrations 
VII 
Plate 20. Apanteles lacteicolor; A.—Adult female. B.—Egg. C.—Hiber¬ 
nating (first stage) larva, before (above) and after (below) evagination of 
hind intestine; h, hind intestine; m, place of attachment of midintestine 
to hind intestine; a, anal vesicle. D.—First-stage larva after feeding in 
spring, ready to pass into second stage; dorsal view: a, Anal vesicle. E.— 
Larval mandibles: Upper left, first stage; upper right, second stage; below, 
third stage.... 
Plate 21. A.— Apanteles lacteicolor: Third-stage larva. Anal vesicle still 
present. B.— A. lacteicolor: Pupa. C.—Third-stage gipsy-moth caterpil¬ 
lar with cocoon of A. lacteicolor. D.-^Two larvae of an undetermined arc- 
tiid from the same egg mass: Above, parasitized by A . lacteicolor; below, 
unparasitized. E.— Meteorus versicolor; Third-stage larva. F.— M. versi¬ 
color: Pupa. G.— M . versicolor: Cocoons. 
Plate 22. Meteorus versicolor: A .—Adult female. B.—Egg. C.—Larva ready 
to issue from egg. D.—Larval mandibles: From top to bottom, first, 
second, and third stages. 
A Hitherto-Unreported Disease op Okra 
Plate 23. A.—A pod of okra collected at Yarrow, Md., showing a typical 
spot caused by Ascochyta abelmoschi. B.—A typical podspot infection on 
the stem of okra... 212 
Potato-Stem Lesions 
Plate 24. Potato-stem lesions four weeks after inoculation: A-H, Plants in¬ 
oculated with Rhizoctonia solani: A, R. VII; B, C, E, R. potomacensis; D, 
Hyp. I; F, R. S.; G, R. VI; H, R. XVI. I-L, Plants inoculated with 
species of Fusarium: I, F. solani; J, K, F. radicicola; L, F. trichothecioides .. 220 
Plate 25. Potato-stem lesions four weeks after inoculation: A-L, Plants in¬ 
oculated with species of Fusarium: A, F. discolor; B, F. oxysporum; C-I, 
F. eumartii; E-H represent portions of the same plant, showing necrotic 
areas throughout the stem; J, F. coeruleum; K, F. solani; L, F. discolor 
var. sulphureum. M, Plant inoculated with Botrytis sp. 1 . 220 
Plate 26. Potato-stem lesions four weeks after inoculation with miscellaneous 
fungi: A, Clonostachys sp.; B, Zygorhynchus sp.; C, Alternaria sp. I; D, 
Alternaria (Macrosporium) solani; E, Phoma sp.; F, Corethropsis sp.; G, 
Chaetomium sp.; H, Acrostalagmus sp.; I-L, Control plants. 220 
Anatomy op the Potato Plant, with Special Reference to the Onto¬ 
geny op the Vascular System 
Plate 27. Origin of leaf and branch traces of the potato: A.—Transverse sec¬ 
tion through internode of a partly mature stem. B.—Transverse section 
through a stem immediately below a node, showing the origin of a new 
trace at a.. 252 
Plate 28. Origin of leaf and branch traces of the potato: A-D.—Transverse 
sections through successively higher nodal regions, showing the origin of 
the lateral leaf traces and of the branch trace. 252 
Plate 29. Distribution of tissues (primary) in the potato: A.—Transverse 
section of the central cylinder and the cortex, showing small stem bundle, 
extent and position of external and internal phloem, proto- and meta- 
xylem, collenchyma and cortex, cambium, and pith. B.—Transverse 
section through part of large stem bundle showing fascicular cambium and 
medullary rays. C.—Transverse section through a large stem bundle. 
D.—Transverse section through somewhat older stem, showing interfasci¬ 
cular cambium and position of external phloem groups and endodermis... 252 
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