INSULAR EXPERIMENT STATIONS. 29 



rapidly in Porto Rico. An experiment to determine the losses in 

 transit of carelessly handled fruit showed that 22 per cent of bruised 

 fruit, 11 per cent of fruit pulled from the stems, 38 per cent of fruit 

 cut by clippers, and only 6 per cent of sound, carefully handled fruit 

 had decayed after 14 days in storage. This shows that the great 

 losses of citrus fruits are due to careless handling. The variety plant- 

 ings of citrus fruits began bearing during the past season, and within 

 a few years the relative value of the more important varieties for 

 planting in Porto Rico should be definitely known. The value of 

 growing cover crops in orchards has been given attention for some 

 time, and it is becoming a common practice to grow them during the 

 period of heaviest rainfall. Tests are now being made of a large 

 number of leguminous cover crops to determine which are best suited 

 to the prevailing conditions. 



Considerable additions were made to the collection of mangoes, and 

 the station now has growing 62 distinct varieties besides numerous 

 &'eedlings. Experiments are in progress with various methods of 

 proiDagating the mango, and the most satisfactory method, at least 

 for old trees, is by bark grafting. Plantings of additional species 

 of rubber-yielding trees have been made and a tapping trial of some 

 8-year-old Castilloa trees was conducted, the herringbone system be- 

 ing used, but this method does not appear suitable to this species in 

 Porto Rico. Plantings of vanilla, cacao, and other economic plants 

 Iiave been made, and the station's collections of these plants are being 

 rapidly extended. A study has been begun on the reasons for the 

 rapid deterioration of vegetables grown from northern seed, 

 lettuce, tomatoes, beans, okra, radishes, beets, and cantaloups being 

 experimented with. 



The Avork in animal husbandry has been largely confined to the 

 introduction and acclimatization of improved breeds of live stock, and 

 some results of the introductions are beginning to be shown. Some 

 trouble has been met with in the introductions of stock by reason of 

 diseases, but methods for overcoming them have been learned. 

 Horses have suffered from osteoporosis, but in several cases the dis- 

 ease has yielded to treatment. Glanders affect horses and mules of 

 the island, but the station stock has thus far been free from it. Ticks 

 infest cattle at certain seasons and tend to keep them somewhat 

 emaciated, but otherwise do little damage. The progeny of x^merican 

 saddle-bred horses bred to native mares have matured into handsome 

 animals that command very high prices. The station has introduced 

 eix more horses during the year to continue the work. The cross-bred 

 zebu bulls introduced by the station in 1909 have developed splen- 

 didly, and they will be used to improve the size of the native cattle. 

 The woolless sheep introduced from Barbados a year ago have proved 

 well adapted to their surroundings, but need some improvement in 



