ALAJUELA AND THE VOLCANO POAS 345 



midribs. The streams were of course much lower and the 

 mud of the roads was beginning to be dust. Although the 

 sun was hot, there was nearly always a high wind and the 

 shade temperature was delightfully cool. The dry season 

 is much more strongly marked on the Pacific than on the 

 Atlantic slope and of longer duration. 



By the end of March, which is toward the end of the dry 

 season, the country about Alajuela had become very dry 

 and hot, the fields and open plazas of the town being brown 

 and parched instead of green with grass. The whole slope 

 towards the Pacific, wherever cultivated for corn or grass, 

 was hazy with smoke from the constant burning over of the 

 dried vegetation. The coffee had begun to bloom, the 

 madera negra trees, although sometimes planted in rows 

 between the coffee bushes to yield shade to the latter, were 

 by this time in bloom but quite leafless and entirely useless 

 in this the hottest and sunniest portion of the year. The 

 madera negra, in fact, although useful as a nitrifier of the 

 soil and very easily rooted from stakes, is now planted much 

 less extensively in the cafetales than formerly. Like the 

 poro, it is a valuable living-fence tree and in March both of 

 these along the fence lines were being pruned to the veriest 

 poles and stumps. In the cafetales the madera negra is 

 being replaced by the "Cuajiniquil" {Inga edulis) and by 

 various "guavos" [Inga sp.) which are equally good nitri- 

 fiers and retain their leaves throughout the dry season. The 

 Ingas are mimosaceous trees with six to eight leaflets and 

 flowers rendered very conspicuous by the long, showy, 

 feathery white filaments. The fruit is a huge pod, vary- 

 ing in shape in the different species but generally flattened 

 like the pod of a lima bean. We photographed one in Car- 

 tago in June that was two inches wide and over a foot long, 

 and contained beans two inches long. The beans of some 

 species, notably /. edulis, are embedded in a sweet white 



