HORTICULTURE. 445 



As found in Porto Rico this species is distinctly dioecious, the monoecious form 

 being very rare. The change of sex in the first tree noted was brought about 

 accidentally. A staminate tree having its terminal bud injured produced shortly 

 afterwards pistillate as well as staminate flowers. The former flowers set and 

 developed good-sized fruits, which bore all the characteristics of normal fruits 

 e.xcept that they were not quite so well filled out. The seeds, which are some- 

 what smaller than normal, have not as yet been tested for germination. Later 

 developing clusters also contained pistillate flowers in the same position as those 

 in the first cluster. 



Investigations thus far made lead to the conclusion that the removal of the 

 terminal bud causes the change. In the attempt to disprove native claims that 

 the removal of the terminal bud in the new of the moon would usually cause this 

 transformation, the author finds that although the moon's phase does not appear 

 to have any control, those trees treated at a fairly definite recurring period are 

 the ones that show change. It is suggested that the plant has definite short 

 cyclic periods of growth, and that it may be necessary to remove the tip at 

 some definite phase of this cycle in order to produce the development of fertile 

 flowers. Further data are being collected in connection with this- subject. 



The cacao fermentation and the preparation of cacao from harvest to 

 shipping", tog'ether with studies on the fermentation of coffee and tobacco, 

 A. ScHULTE {Die Kaktio-Fcymentation uiid die Verarbeitinig dcs Kokaos von der 

 Ernte his sum Versand soirie Kaffee- und Tabak-Fermcntatioiis-Studien. Ber- 

 lin, 1908, pp. 35). — A summarized account is given of cacao fermentation studies 

 started by the author in Kamerun in 1899 and later continued in Germany, to- 

 gether with the application of the results on a cacao plantation on St. Thomas 

 in 190.3. Directions are given for harvesting, fermenting, drying, and shipping 

 cacao, and suggestions relative to the practical application, without important 

 changes, of the processes used by the author in his experiments. Brief studies 

 relative to the fermentation of coffee and tobacco are also reported. 



As a result of his investigations, the author divides cacao fermentation into 

 2 stages, (1) the alcohol and acetic acid fermentation, and (2) oxidation. He 

 bases the production of good cacao upon a correct execution of both stages. 

 During the alcohol and acetic acid fermentation, the seeds are freed from the pulp 

 and the shells softened, thus favoring oxidation. The oxidation of the astrin- 

 gent substances is the important feature of cacao fermentation. An oxidation 

 temperature of from 40 to 4.5° appears to be most favorable for the quality of 

 the product, and a moisture content of 15 per cent was found to be most favor- 

 able to oxidation and at the same time unfavorable to butyric acid fermentation 

 and the formation of mold. When the oxidation process is conducted satis- 

 factorily a delicate white efflorescence forms on the beans, which may be taken 

 as an indication that the cacao has been oxidized. Oxidation should be con- 

 tinued only until the majority of the beans have taken on a brown color, as 

 if the oxidation is continued until all the beans are brown, the flavor and aroma 

 are weakened. The proper length of time for oxidation can only be determined 

 by experience and may vary in different cacao districts and with different kinds 

 of cacao as well as with different harvesting methods. 



As a result of his brief studies on the fermentation of coffee and tobacco, the 

 author concludes that oxidation is as important with them as in the fermenta- 

 tion of indigo, tea, and cacao. 



The unheated greenhouse, K. L. Davidson {London, 1D07, pp. VIII-{-2.'i8, 

 pis. .'/6) . — In this popular work the author makes a plea for a more frequent use of 

 the uidieated types of greenhouses by amateur gardeners and gives considerable 

 information, based on many years of practical experience, relative to the man- 

 agement of these houses and to suitable ])lauts and their cultural treatment. 



