Vol. XV. No. 360. 



THE AGRICULTURAL NEWS. 



51 



believe.s that they play a part in plant nutrition somewhat 

 similar to that played by accessory food bodies in the 

 nutrition of animals. Professor Keeble does not think that 

 Professor Bottomley's evidence is strong enough at present 

 to support this conclusion. Nevertheless, Professor Keeble 

 says, it should not be dismissed lightly; rather it is a case 

 like so many in biological science, in wliich a just judge would 

 order a fresh trial. It is understood that such a trial 

 is to be conducted at Kothamsted, and it is hoped, for the 

 sake of horticulture and agriculture, that it may lead, on 

 one hand, to the demonstration of the fertilizing value of 

 bacterized peat, and on the other, to the just judgment of the 

 case for auximones. 



CHANGES THAT OCCUR IN THE 

 RIPENING COCO-NUT. 



Few tropical plants affijrd greatei' opportunities for 

 profitable study along physiological lines than the coco-nut. 

 This has been realized in the Philippines, where Professor 

 Copeland has been a pioneer in connexion with this special 

 .study. A continuation of the work is a thesis in a recent 

 issue of the Philipjnne Affriculturist and Forester, by one 

 of the .students of the Philippine College of Agriculture, deal- 

 ing with what happens in the process of coco-nut development. 



In describing changes in colour, sir.e and weight that 

 take place, it is noted that self-pollination is hardly possible 

 in the case of the coco-nut flower, because before the stigmas 

 become receptive, all the staminate flowers have been shed. 



During the first period of growth there is an accumulation 

 of sugar and soluble nitrogenons substances in the milk. At 

 this stage the husks are soft, and the nut generally has its 

 greatest diameter along the main axis. During the second 

 period of growth cane sugar appears in the milk, and the 

 specific gravity of the milk is high. Water is lost, though the 

 total weight of the nut continues to increase. The nut 

 begins to increase in diameter. During the closing period 

 of ripening there is a sudden li.se in the content of oil in the 

 meat or endosperm. The specific gravity of the milk falls, 

 the shell becomes impervious, and the drying out of the husk 

 results into a loss of weight, which overbalances the gain in 

 weight due to other changes. The meat begins to form 

 when the nut is about six months old. Only invert sugar is 

 present in the meat when it is 0' 1cm. thick. The general 

 tendency of the nitrogen content of the meat is to rise. 



In continuation it is stated: — 



'As the nut becomes older the evaporation of the water 

 from the husk causes an apparent increase in the percentages 

 of meat, .shell, and water; but if the actual weights are 

 considered, it will be found that the weight of the shell 

 undergoes little change during the latter stages of ripening, 

 while the weight of water appears to be subject to irregular 

 fluctuations tending towards a decrease. The actual weight 

 of the meat does not appear to increase much, if any, during 

 the last 100 days, though analysis during this time 

 shows that the endosperm changes gieatlj' in composition. 

 Most of the oil in fact is produced after the period 

 when the nuts have become very decidedly brown. 



'When the nuts germinate, the percentage of sucrose and 

 invert sugar contained in the milk incieases very rapidly. The 

 percentages of these two sugars in the meat increase likewise. 

 The nut that has just begun to sprout appears to make use of 

 the nitrogenous constituent of the end<^isperm before much of 

 the cil is removed, though the fact that but two nuts were 

 analyzed will leave this statement sonv what in doubt. 



'In this locality it appears that nuts require in the 

 neighbourhood of 370 to 410 days to tj^come fully ripe, count- 

 ing from the moment the spathes open.' 



IS THE FERMENTATION OF CACAO 

 NECESSARY? 



Realizing the possible importance of this question raised 

 by M. Perrot at the Third International Congress of Tropical 

 Agriculture, we published a note drawing attention to the 

 subject in this .Tournal for ^^eptember 11, 191.3. M. Perrot's 

 suggestion is whether it is really necessaiy to subject cacao 

 beans to any fermentation at all, at least on estates. His 

 method of preparation consists in treating the beans with 

 washing soda to remove the pulp, and then steaming the 

 beans in order to prevent fermentation changes during storage 

 and shipment. II. Perrot reported that a firm of chocolate 

 makers in France had stated that beans prepared by the 

 above method were in no way inferior to fermented cacao, and, 

 on the whole, were distinctly more uniform. 



In a recent issue of Tropical Life (December 191-5), an 

 article appears by Mr. A. W. Knapp, B.Sc, F.I.C., containing 

 the results of a technical e.xamination of cacao prepared in 

 Trinidad according to M. Perrot's method. The following 

 are the conclusions drawn concerning the practical valus 

 of the new method: — 



(1) Cacao obtained by the above method is similar in 

 appearance to ordinary unfemiented cacao, and would therefore 

 obtain a lower ])rice than fermented cacao. (2) The new 

 process would require at least as much intelligent control 

 as the present fermentation process actually gets. Wherever 

 any good attempt at fermentation is made, the cacao is 

 a satisfactory commercial product. Those who do not take 

 the trouble to ferment properly are unlikely to go to the 

 expense of having a steam sterilizer fixed. (.3) M. Perrot 

 considers that cicao obtained by steaming is in no way 

 inferior to the product obtained by fermentation, but actually 

 says that fermentation may be detrimental to cjuality. 

 Admittedly, there may be a loss in weight, but the quality of 

 bean, according to Mr. Knapp, is always improved by fermen- 

 tation. Cacao prepared by the new method has a purplish 

 colour, and a more inferior odour and astringent taste than 

 fermented cacao. (4) Cacao very similar to the steamed 

 cacao (though not cjuite so free from pulp) is produced by 

 the much cheaper method of simply drying the beans in the 

 sun. Beans thus dried are not liable to spontaneous chemical 

 change as M. Perrot appears to think. (5) Cacao prepared 

 bj' the new method takes longer to dry than ordinary 

 fermented cacao. (6) If M. Perrot's suggesiion be followed, 

 Mr. Knapp points out that it would be necessary to carr}- on 

 fermentation when the cacao arrives at the factory. If this 

 were done it would be of considerable value, as it wotdd 

 facilitate the supply of cacao in a more uniform condition. 



But Mr. Knapp concludes: 'It should be noted, however, 

 that it would only be a step to greater uniformity, as the 

 cacao arriving from one district, or even one plantation, 

 contains several types of beans. Further, the sugary pulp, 

 which is the material in which fermentation starts, has been 

 removed. And last, but not least, the advantage that the 

 manufacturer would get in the way of more complete control 

 of his raw material would be compensated for by the extra 

 cost of this fermentation process. Nor would there be 

 any saving to the planter, for the plant to sterilize and brush 

 the pulp from the beans would be as costly as the present 

 fermenting chambers. 



'I regret that I can see no practical advantages in 

 M. Perrot's suggestions, for I admire his brave attempt to 

 apply scientific method to cacao preparation, but for the 

 present I think we cannot do better than encourage the 

 planters to ferment their cacao by those methods which they 

 know to be the best.' 



