HORTICULTITRE. 45 



The index is arranged in alphabet ieal order and consists of a fairly complete 

 list of the cultivated varieties of pears, embracing both leading names and their 

 synonyms, together with brief descriptions and histories of varieties, including 

 origin, form, size, color, texture, flavor, quality, and time of maturity. An 

 index to the American literature of the pear from 1804 to 1"J(J7 is appended. 



Report of the coffee expert, J. W. van Leenhoff (Porto Rico .S7rt. Ri)t. 1907, 

 pp. 3!), J/O). — Storms lasting continuously from November 25 to December 14, 

 15)06, and again from March 26 to March 2S, 1907, did much damage to old and 

 young trees, especially in less protected places, and showed the necessity of 

 many more wind-breaks. As a provisional protecticMi i)]antains were planted 

 between the rows, to be removed as soon as the shade had grown to sutHcient 

 height. Although the claim of Porto Rican planters that young coffee wants 

 heavy shade has not been proved, it does appear that many shade trees for wind- 

 lireaks may be required. 



The experiments in improving an old coffee grove were continued and the 

 yields determined (E. S. R., 18, p. 1049). The crop from 10 acres in 1902 

 was 3,387 lbs. In the following year the plat was divided into 10 1-acre plats, 

 on each of which a different method of treatment was followed, as has been 

 previously noted (E, S. R., 16, p. 144). In all 1,106 trees were removed and the 

 others trimmed up. In 1903 the yield from the 10 acres was in all 1,623 lbs. 

 The yield has increased each year, and in 1906, 4,349 lbs. was secured. Full 

 details of the experiments are to be published later in bulletin form. 



The total cost of gathering and preparing 100 lbs. of coffee for market is 

 estimated at $4,335, and the average price obtained for the same amount as 

 .$10,885. Estimates are given of the cost of the new plantings of coffee. The 

 net cost per acre to the end of the third year was $83.70. 



The fermentation of cacao and of coffee, O. Loew {Porto Rico Sta. Rpt. 

 1901, pp. Jfl-55, fig.s. 2). — Studies were made by the author relative to the pur- 

 pose and necessity of, and the kind of action involved in, the fermentation of 

 cacao and coft"ee. Several investigators are cited to show that a great differ- 

 ence of opinion exists along these lines. 



The chief purposes of the fermentation process with cacao are given as the 

 removal or contraction of the pulp surrounding the seeds, the loosening of the 

 connection between the seed and its testa, and the development of the color and 

 the improvement of the taste. The action of the fermentation process in bring- 

 ing about these changes is discussed. 



The author concludes that the fermentation process itself is due primarily to 

 yeast cells, which multiply rapidly in the saccharine juice oozing from the 

 pulped cacao, or slime tissue, and pi'oduce alcohol and carbon dioxid. Bacteria 

 also develop rapidly after a certain time and ozidize the alcohol formed by the 

 yeast, either wholly or partly, into acetic acid. These processes cause a rise 

 of temperature and the death of the cells of the seeds and slime tisue, where- 

 upon the juice of the slime tissue, more or less altered, collects at the bottom of 

 the receptacles, together with the acetic acid produced. By thus shrinking the 

 slime tissue the quick drying of the seed is facilitated, the adhesion between 

 the seed and its envelope is loosened, and the envelope is liardened. 



P'ermentation also acts indirectly in killing the seed cells, thus liberating 

 oxidizing enzyms, which cause the formation of a brown coloration by oxidation 

 of the tannin of the seed. This coloration is increased during the drying process 

 and finally by the roasting. The taste of the raw cacao bean is not only altered 

 by the partial oxidation of tannin during the fermentation or sun drying of the 

 seed, but also by products of roasting. Both the oxidizing enzyms and the flual 

 roasting process assist in developing the aroma. 



