139 



it is known that in some cases the ants take the trouble to carry 

 apliides from place to place in order that the aphides mav thrive. 

 Thus when the pasturage for the aphides l^ecomes poor, the ants 

 remove them to better feeding-grounds. 



Whether these mealy bugs wander from the base of the ])ine- 

 apple to the top in order to establish new colonies I do not 

 know. It is possible that they may be carried from the base 

 to the top by ants. Such a thing would be no more wonder- 

 ful than many of the things ants are known to do in this con- 

 nection. 



At any rate, it is certain that the mealy bugs in some way find 

 their way from the base of the pineapple to the tip. 



PINEAPPLE ROT. 



(That is Tliielavioiysis ethoceticus, Went.) 



Pineapples carried off by Thiclaz'iohsis often rot from the top. 

 In this case the fungus makes its way down into the pine- 

 apple by way of the fibers of the core, as may be easily seen 

 when the characteristic black color develops. The same or 

 similar phenomena occur wdien the rot makes its way in at 

 the side of the fruit, as it less frequently does. The reason 

 the rot enters at the bottom or the top has already been indi- 

 cated. It is because the insect attacks, apparently necessary 

 as a preliminary, occur principally at the bottom and the top 

 of the fruit. 



In its final stages, a fruit that has rotted from above will 

 permit of the easy removal of the top. It pulls away easily 

 and the black fibers of the core of the fruit come away like a 

 sort of root system. This is shown in Fig. 8, which il- 

 lustrates, in an exaggerated w^ay. what may take place in 

 using tops for new plantations. In the case illustrated there 

 would be no question in the mind of anyone that some of the 

 rot is taken away with the removed top. It can be seen. 

 Now, if in such a case the lower part of the axis of the top 

 be examined it will be seen that the rot- ceases a little way 

 into the top. The black color of the rot can be seen in the 

 hard tissues of the center of the top. The fungus actuall\\ ex- 

 tends some distance beyond the black coloration. This is an 

 important matter to understand, because it shows how a 

 planted top may contract the disease. It may even be that 

 through carelessness such a top with rotten tissue at the bot- 

 tom is planted. The more important thing to note, however, 

 is that this observation proves that the axis of flic top can 

 contract the disease. The tissues of this part of the pine- 



