Vol. XVII. No. 428. 



THE AaUICULTirilAL NEWS, 



201 



from the unravelling of the cotriplex ancestry of the 

 natural varieties, whilst similar results from the retangl- 

 ing of the new strains thus obtained are compara- 

 tively rare, and are very elusive.' 



Those who are interested in the introduction of 

 new seedling canes into their fields will, doubtless, in 

 the light of these remarks, carefully consider the results 

 which they are obtaining from their efforts. It will be 

 observed that, in Professor Harrison's view, the work 

 of finding promising seedlings is much more difficult 

 when it is required to have canes that will ratoon well; 

 \vhen plant canes only are grown, the problem is rela- 

 tively simple. 



The question of the stability of seedling canes pro- 

 pagated by cuttings has long been under investigation. 

 Some have held that these canes would prove stable, and 

 indeed in the early days of the work this was the com- 

 monly accepted view: now, however, many are doubt- 

 ing this, and Professor Harrison appears to be amongst 

 those who are convinced of the tendency towards early 

 senile degeneracy on the part of these seedlings. It is 

 observed that, in some districts where sugar-cane is 

 cultivated, there is a tendency to substitute one new 

 seedling after another in the hope of obtaining ever- 

 increasing yields. Where adequate records exist, it 

 would be well to examine these carefully, in order to 

 see whether the newly introduced varieties retain their 

 productiveness in full degree, or whether they fall off, 

 so that the substitution of successive new varieties 

 merely serves to maintain the sugar production at a 

 hisrh level, but does not tend to raise that level to the 

 extent that is hoped and desired. Now that it is the 

 commonly accepted practice on the majority of West 

 Indian sugar estates to weigh the canes which are 

 delivered to the large factories, and seeing that in the 

 factories continuous analyses are made of the juice 

 obtained from these canes, there should be in existence 

 some data whereby it may be possible to learn some- 

 thing definite concerning the stability or otherwise of 

 seedling canes during the years subsequent to their 

 introduction into cultivation on a large scale. 



ytill the fact remains that the continued produc- 

 tion of new seedling canes is a matter of moment for 

 the sugar industry. This work affords means of combat- 

 ing many of the forms of fungus disease to which sugar- 

 canes are liable, and it also affords the means of main- 

 taining the level of production, even if it does not tend 

 to raise that level so rapidly as was at one time hoped 

 might be the case. It is therefore work essential for 

 the well-being and development of the industry, and 

 should be carried on continuously. 



SUGAR AND THE TEETH. 



1(1 the course of a paper in Fatmfis' Bulletin 535, 

 Lnited States Department of Agriculture, on Su^ar and Its 

 Value as Food, there occurs the following information ia 

 regard to the effect of sugar on the teeth, which should be 

 of interest: — 



'It is often said that sugar is harmful to the teeth, but 

 the facts seem to be as follows: According to the theory 

 universally accepted, the decay of the teeth, technically called 

 canes, is caused by bacteria, such as are found in every 

 mouth, entering the soft portions of the teeth through defect* 

 in the hard outer covering. If acid is present in the mouth, 

 and especially in the interstices of the teeth, it tends to eat 

 into the enamel and thus provide an entrance for the earies- 

 producing bacteria. Ordinarily, saliva is alkaline and protects 

 the teeth against this danc,'er, but when it is in contact with 

 sugar or starch, acid is produced, hence a carbohydrate mate- 

 rial lodged upon the teeth may be the indirect cause of caries. 

 Some authorities hoLl that certain forms of sugar cause the 

 flow of a less alkaline saliva, but this point is not fully estab- 

 lished. In general, it is believed that starch is not as dan- 

 gerous as sugar, and that the form and manner in which the- 

 material is eaten is a more important consideration than its- 

 exact chemical structure. Soft foods are especially Ukely to- 

 cause trouble, both because bits of them may remain on the 

 teeth where they form "plaques" which are centres of bacterial 

 action so long as they remain, and because they are swallowed 

 without much chewing and thus do not rub the food "plaques" 

 or other deposits from the teeth. Modern specialists consider 

 that the cleansing action of proper mastication is as important 

 for the preservation of the teeth as the regular use of a tooth- 

 brush, important as this last is. Any soft carbohydrate food 

 eaten alone is much more likely toleave a deposit on the 

 teeth than if it is eaten in combination with other foods. If 

 candies are eaten by themselves, they are more likely to 

 cause the development of acid in the mouth than if they are 

 taken during a meal. Some physicians advise finishing the 

 meal with acid fruit for the sake of lessening the chances of 

 carbohydrate material clinging to the teeth. While soft 

 foods may possibly cause trouble, the hard ones may also be 

 dangerous, especially to diseased teeth, as the effortto crush 

 them may tend to increase flaws in the enamel. Such things 

 as hard crusty food, hard candies such as lemon drops, stick 

 candy, etc. may be dangerous in this respect, though investi- 

 gations by G. V. Black on the crushing force of the teeth, 

 have proved that sound teeth are capable of crushing much 

 harder substances than these without injury.' 



Medicinal Herb Growing.— Dr. David Kills.. 

 Professor of Botany in the-Royal Technical College of the 

 University of Glasgow, has written a book to foster tha- 

 giowing movement for the revival of herb cultivation in this 

 country [Great Britain), a movement which was organized 

 with the object of supplementing the supply of some of the 

 more urgently required drugs, such as digitahs, belladonna, 

 and opium, at the beginning of the war. The industry, 

 which now adds to a useful extent to the synthetic drugs, 

 has greatly developed in the last two years, and private 

 growers and collectors, tlnnlis to good organization in sever.a 

 countries, have reinforced the eflforts of the professional 

 firms. The book, which is full of varied information on thr 

 subject, is entitled .\hdunial Heibi and Poisonous J'inntf, 



and will shortly be publi.shed by Jlessrs. Blackie i: Son • 



Thi Field, 3\x\y 19 IS. 



