been pre-disposing causes, particularly drought. Colletotrickum is 

 often found following after the rind disease, that is in so far as 

 external appearances show. As to which is primary internally 

 appears to be immaterial, sometimes one appearing first and some- 

 times the other. Both are considered wound parasites or as capable 

 of attacking weakened canes only. A further note on the occurrence 

 of this fungus mil be given under ''Diseases of Cuttings." 



There are other forms which are morphologically similar to Col- 

 letotrickum falcatum. For this reason the finding of what is sup- 

 posed to be C. falcatum on other plants should be demonstrated by 

 cross-inoculations. It has not as yet been proven that this fungus 

 does occur on other plants. Edgerton (25) has attempted by cross- 

 inoculations to ascertain whether C. lineola on Jolmson grass (Holcus 

 liahpense) may not be the same as C. falcatum on cane, as it appears 

 to be morphologically, but as yet he has been unsuccessful in this. 



Although not definitely proven to beC. falcatum a form identical 

 with it in appearance has been found on dead leaf-stalks of the com- 

 mon papaya (Carica papaya). As a matter of fact more than one 

 form has been found on cane, as is noted on another page, and until 

 more is known about the relationships of these various forms the 

 question of the occurrence of C. falcatum on other plants can not 

 be satisfactorily determined. 



Description of Colletotrichnm falcatum. — The fungus produces an 

 internal red rot of attacked canes, often limited in otlierwise healthy 

 stalks to the injured internodes only, but in more severe cases pro- 

 gressing up and down the stalk, more rapidly along the vascular 

 bundles than in the surrounding tissues. After the rot has progressed 

 some time characteristic whitened spots appear in the center of the 

 red areas. Beyond a withering of the leaves no other symptoms 

 are present. The fungus does not fruit until the stalk has become 

 dead and thoroughly rotted, when it produces black velvety patches 

 on the surface more generally near the nodes. It is very common 

 to find tlie fungus fruiting on dead leaves, or on the margins and 

 tips of leaves which are dying. 



COLLETOTRICnUM FALCATUM Went. 



With setae sometimes seriate, sometime congregate in a pscudo- 

 concentacle. 100-200X4 mu.. sooty, pale above; conidia falcate 

 25X4 mu., at the base of the setae supported by basidia. ovoid, 

 20 X 8 microns, hyaline or dark. 



Porto Ktco. — On cane Rio Piedras, April 10, 1911, 4050. April 

 21. 1911. 4055. June 5. 1911. 4068, April 20, 1912, 4336, May, 1912. 



193 



