25 



of these berries nor from those of the spotted berries. Such in- 

 jurious effect as it may have on the grain must be due to the shrink- 

 age resulting from increased loss of water from the spotted fruits, as 

 well as the admittance through the weakened tissue, at the point 

 attacked, of other organisms which attack the grain directly. Of 

 these several haA^e so far been found, the most common being a 

 Fusarium, identical, apparently, with this stage of the Sphserostilbe, 

 already mentioned. The injury resulting from the spot seems to 

 depend on the age of the fruit attacked. When the infection takes 

 place on undeveloped fruits the resulting injury is greater, but if 

 the grain has begun to harden before the spot develops fully it may 

 escape injury. 



Another source of the inferior quality of coffee from sun-exposed 

 fields is to be found in the " granos vanos," berries that seem to be 

 well filled out and good, but which are easily recognized at the time of 

 picking by their yielding readily to the pressure of the hand and also 

 by the dried, blackened pedicels. The name could be applied as well to 

 the sound-appearing berries with bad grains mentioned above, but for 

 convenience it is here used to indicate those the injury to which is due 

 to the supply of food material having been cut off, as shown by the 

 dead pedicels. Not isolated berries alone, but often all on one branch 

 or the entire tree are affected in this way. The shriveled grain con- 

 tained in these berries remains free from fungi or bacteria for a long 

 time, the injury being clearly not due to these organisms. The black- 

 ened tissue of the branch at the base of the pedicels always contains a 

 Glcesporium, and occasionally a Fusarium. But neither of these 

 fungi was found to be able to attack the tissue of healthy green 

 branches when tried out by inoculations with pure cultures. It would 

 seem that they are only able to attack weakened trees exposed to full 

 sunlight and subject to the unfavorable soil conditions accompanying 

 such exposure. Not all the trees in unfavorable conditions produced 

 berries of this sort. What the proportion may be was not determined, 

 but it is only large in the first picking. This was omitted in the 

 earlier work, and in that of the last year the " gi-anos vanos " were 

 separated out, so that the result can not be affected to any extent by 

 their presence in the samples. The hormiguilla {M yrmelachista sp.) 

 is to some extent the cause of these " empty berries," as it often injures 

 the base of the fruit-bearing branches and sometimes the pedicels, 

 thus cutting off' their supply of food. 



It is known that the soil in well-shaded places is more uniformly 

 moist than in more exposed situations, and no doubt the benefit of 

 shade in coffee is in part due to better soil conditions, especially with 

 regard to moisture. The soil in unshaded places becomes very dry in 

 the season of little rains and also very hard where of the clay type. 

 The unfavorable condition as to moisture is made worse by the pres- 



