332 Journal of Agricultural Research voi. iv. No. 4 



have made a growth of 8 to 10 inches, the leaf-spot may make its appear- 

 ance and be thus carried over the winter on the dead leaves or in lesions 

 formed on the vines. If these plants are left in the beds a second season, 

 the fungus may make its appearance early in spring and increase until by 

 midsummer no vine is wholly free from disease. The leaf-spot may first 

 appear either as a mere dot or as a water-soaked area. With the ad- 

 vent of moist warm weather the former usually leads to the latter. On 

 drying the water-soaked spot becomes tan-colored with a red margin. 

 Plate L shows the general appearance of the disease on C. panicidata. 

 The older leaves are badly diseased or dead, and the fungus has grown 

 down the petiole to the node, where in time the vine may become girdled. 

 The younger leaves show the early stages of the leaf-spot. The stem 

 shows the lesions, reddish in color, formed at the nodes and on the inter- 

 nodes. Later these take on a gray color. Plate LI illustrates a group 

 of leaves of C. paniculata with spots that are zonate, owing to the unequal 

 growth of the fungus under the influence of changes in temperature. The 

 newly formed spot has a dark margin of red tissue and a lighter center- 

 Pycnidia are produced on the diseased leaves. Succulent growing tissues 

 succumb more readily to the disease than do the woody stems. In the 

 latter it may require a month for the fungus to pass a node. Plate LII, 

 figure I , shows a portion of a vine of C. paniculata 44 inches long on which 

 the lower leaves were waited, while the distal ones were still turgid. The 

 fungus entered through the stub a. It girdled the stem and disinte- 

 grated the upper roots, leaving the central cylinder as the only means of 

 communication with the healthy roots below. Pure cultures of Ascochyta 

 clematidina were obtained from the boundaries of the lesion. Pycnidia 

 were formed on the stem above the ground. In other cases pycnidia have 

 been found on the epidermis, while the tissues underneath were healthy. 

 Some of the large- flowered kindb of clematis are grown from seed, 

 but in America the majority of those cultivated are hybrids. They are 

 propagated from cuttings taken from rapid-growing, disease-free vines. 

 The cuttings are made in May or June and consist of a single node with 

 the attached leaves and the intemode below. They are placed in moist 

 sand and exposed to bottom heat or else grown in forcing frames. In forc- 

 ing frames the humidity and temperature are usually higher than is found 

 in the average greenhouse. Under these conditions, if the spores are pres- 

 ent, a leaf-spot may be formed, and the entire cutting may be killed or the 

 fungus may be halted at the node. The fungus that has been checked 

 may again become active when the cuttings are potted and placed in the 

 greenhouse, or new infections may take place on the leaves. In the 

 fall some of the plants are placed in storage, while others are kept over 

 winter in the greenhouse and the tops used for cuttings. In the fol- 

 lowing spring both lots are transplanted into the open field and, unlike 

 C paniculata, are not allowed to trail on the ground. Experience has 



