DISEASES OF PLANTS. 549 



The rhief clanger from these brown rot cankers on the wood consists in the 

 possibility of infection the followinj; spring and summer from the numerous 

 tufts of conidia which iJroject from the cankered areas. 



The occurrence of New York apple canker in England, E. S. Salmon (Ganl. 

 Citron., 3. ser., J,7 (ID JO), A'o. 1^17, pp. 258, 2.7.9, fig. /).— Attention is called to 

 the occurrence of this disease on the branches of a pear tree. The microscopic 

 and macroscopic characters of the fungus {Sphwropsis maiorum) are figured 

 and described and suggestions given for its control. 



Leaf blight of the pear and quince, Ethel M. Doidge {Transvaal Agr. Jour., 

 8 {1910). .Vo. 31, pp. J,0o, .'{66, pL 1).—X descrlptuMi is given of the leaf blight 

 {Enlomo.sporiiiDi maculatutn) which attacks the pear and quince, together with 

 suggestions for its control. 



The Panama disease, E. Essed {Ann. Bot. [London], H {1910), No. 9Ji, pp. 

 488, 489, figs. 3). — A preliminary report is given of a fungus disease of the 

 variety of bananas known as Gros Michel. This disease has been noticed in a 

 number of localities in Central America and northern South America, where it 

 has seriously threatened the banana industry. 



As a result of a preliminary examination, the author concludes that the 

 disease is due to one of the Ustilagineje, probably in company with a member 

 of the Chytridious order. The final results of his investigations on this disease 

 are promised in the near future. 



The relation of black rot of cacao pods to the canker of cacao trees, J. B. 

 ROKEK {Bill. Dept. Agr. Trinidad, V {1910), A'o. 6'i, p. 38). — Inoculation experi- 

 ments with Phytophfhora omnirora have shown that this organism causes the 

 black rot of the pods as well as the canker of the trees. A bulletin describing 

 both diseases in detail, together with the organism causing them, is in process of 

 preparation. 



The root disease of the coconut palm, T. Fetch {Circs, and Agr. Jour. Roy. 

 Bot. Card. Ceijlon, J, {1910), No. 2 J,, pp. 323-336) .—Attev a discussion of the 

 root disease of the coconut of various countries, a general description of the 

 symptoms of this disease as it appears in Ceylon and the results of studies as to 

 its cause are given. 



The most general symptoms of the root disease of coconuts are as follows: 

 (1) The outer leaves wither and drop, usually remaining for a long time sus- 

 pendefl vertically around the stem; (2) the tree becomes barren owing to the 

 suppression of the flowering branches; (.3) the new leaves are successively 

 smaller, so that the crown becomes a mere handful of erect yellowish leaves; 

 and (4) finally these small leaves wither and the bud decays. 



A twenty-five year old tree in the earlier stages of the disease was dug up and 

 a cross section was cut from the butt. This when examined after 24 hours was 

 found to have developed white tufts of hyjjhie from each vascular bundle 

 toward the perii)hery of the stem. The section was ?>G cm. in diameter, and 

 the affected vascular bundles occui)ied an outer zone from 4 to G cm. in width. 

 Both surfaces of the section were similarly affected. On cutting the sections 

 vertically the vessels of the vascular bundles were found to be filled with white 

 hyphje from one end to the other. The outer vascular bundl(>s. but not the inner, 

 were completely filled with the mycelium of this fungus. Pieces of this section 

 when placed in glass dishes in the laboratoi'y and kept moist for 4 months 

 produced the well known sporophores of Fomcs lucidus. 



The results of these experiments seem to indicate that the true cause of the 

 coconut root disease in Ceylon is the fungus /•'. lucidus, the mycelium of which 

 permeates the outer tissues of the butt end of the tree, especially the vessels of 

 the vascular bundles, gradually filling them and thus shutting off the water 



