IQOS] 



ITERATURE 



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are abundant upon leaf scars and h\'igs. . The life-history issiimmed up as 

 follows : 



The spores, scattered profusely over the limbs, germinate as soon as enough rain 

 has fallen to wet them up thoroughly, usually in December or January. Spores lying on 

 the green bark of new shoots penetrate the tissue and cause the characteristic spotting. 

 Spores lying about the bud scales produce a mycelium which penetrates and kills 

 outright both the bud and quite an area of surrounding bark, the spot extending from 

 one-fourth to one inch in length. On the spots spore pustules are developed. 



The fungus w^as cultivated in beef agar, in ordinal}' agar, and on sterilized 

 peach twigs. The colonies are black with distinct zonal arrangement of conidia. 

 No indication of an ascigerous stage was found. — F. L. Stevens. 



Fungus diseases of sugar cane. — Butler ^' has given an account of the fungi 

 attacking sugar cane in Bengal. The most serious disease seems to be caused by 

 Collefotnchum jalcatum Went., which causes a rot of the stalks that spreads from 

 the base upward. In the early stages of the disease the fungus greatly reduces 

 the sugar-content of the cane. With the disappearance of the cane sugar there is a 

 simultaneous increase of glucose. This is attributed to the inverting action of 

 the fungus, and by proper flask experiments it was sho%\Ti that the fungus has 

 the power of inverting cane sugar. All parts of the cane are attacked by the 

 fungus. On the stem it is often accompanied by a form of Melanconium {Tri- 

 chospJiaeria Sacchart)^ which was once regarded as the cause of the most destructive 

 cane disease of the West Indi^, namely the "rind disease." BrriER believes, 

 however, that the Melanconium is only an accompanying fimgus and that Colleto- 

 trichum jalcatum is possibly the cause of the famous "rind disease. 



A number of other fungi are more briefly described. UstUago Sacchari 

 Rabenh. tmnsforms the growing axis into a long spore sac. Diplodia cataoicola 

 (P. Henn.), which was originally found on Thec^onui cacao^ is said also to attack 

 the stems of cane. Cytospara Sacchari Butl. is d^cribed as a new species also 

 found on the stems of cane. Thielaviopsis ethaceticus Went, is the cause of the 

 pine-apple^' disease of the young sets, while SpJiaeronema adiposum Bud. some- 

 what resemble the latter in its effects. The most serious leaf diseases are the 

 brown leaf spot caused by Cercospora longipes Butl., described as a new species, 

 and the well-known ring-spot, found everywhere on cane leaves in the tropics and 

 caused by Leptosphaeria Sacchari Br. & H.— H. Hasselbrixg. 



Cyanogenesis in plants. — Trecb returns to a dfecussion of the origin and 

 distribution of hydrocyanic acid.^' Incidentally he adds in one of his tables to the 

 Kst of plants in which HCX has been found (as given by Greshoff at the York 

 meeting of the B. A. A. S.) six ^nera and sixteen species. HCN as a rule, in 

 hot countries at least, disappears from the leaves before their fall, the contrary 



^7 BtriLER, E. J., Fungus diseases of sugarcane in Bengal. Mem, Dept. Agric. 

 India Hot i: no. 3. pp. 53. pis. 11. rgo6. 



>8 TsEUB, M., Nouvelles recherches sur ia r6Ie de Facide cyanhydrique dans ks 



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plantes vertes, IL Ann. Jard. Bot. Buitenzorg 21: 79-ro6- pb. /, 2. 1907. 



