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only under expert advice, and even then to proceed slowly, 

 carefully watching results, and thus securing the necessary 

 personal experience. To do otherwise is to run the risk 

 of damage to crop and absolute failure, where, under 

 proper management, success might have attended the effort. 

 Studies in Cacao Disease. Diplodia. — ^In writing of this 

 there is no intention to scare or lead planters to become 

 unduly anxious for their plantations, but merely to present 

 actual facts which should be known to every one interested 

 in the cacao industry. There can be no doubt that 

 the destructive microscopic parasites causing disease in 

 cacao are plentiful and persistent, and that the amount of 

 damage they are capable of causing is not as yet recog- 

 nised or realised. Among these diseases, one of the most 

 prominent is that described in Stockdale's pamphlet as 

 causing " Brown Rot " of the pod, and " Die Back " of 

 the branches. This fungus is a " facultative parasite," 

 or one which, though at first a " saprophyte," or grower 

 upon dead matter, can and does afterwards become a very 

 destructive parasite. It is described by Howard, Stockdale 

 and others as bearing two kinds of spores, by the growth of 

 which it spreads rapidly ; how rapidly will be seen later. 

 The first is one-celled and " hyaline " or colourless, while 

 the second is brown in colour and once septate or divided 

 into two cells, the latter being the mature stage of the 

 former. These spores can both germinate on any wound 

 or abrasion of the cacao-tree. Stockdale records that 

 " Howard's experiments pointed to this fungus being a 

 wound parasite and capable of affecting sickly trees." 

 This fungus is scientifically known as Diplodia cacaoicola 

 P. Henn. Recent experiments with the two forms of 

 spores show that the hyaline spore does not germinate so 

 quickly as the mature form, and grows from one point 

 only until it approaches maturity, when it may grow from 

 two points. The mature spore, however, produces growth 

 from each of its cells, at or about the same time. The rate 

 of growth made in our cultures of the two forms is as 

 follows : For the hyaline or immature spores 1.55 hours, 



