714 



THE TROPICAL AGRICULTURIST. 



[April r, 1884. 



befoimd m the uninjured husk-of the almond, and it seems 

 at first sight more jirobable that the hrritation caused by a 

 tungoul parasite should cause a greater flow of the natural 

 product. ]ust as the irritation caused by an insect causes 

 the deyelopment of gaUs. "Whether this "be so or not, the 

 discovery that it is possible to produce artificially a free 

 flow of gum IS a valuable discovery, since it may now be 

 tound advantageous to cultivate certain trees for the pur- 

 pose. Tlais IS a point which might well attract the atten- 

 tion ot the Forestry Department, since the importations 

 of gum arable at the present time consist largely of a 

 variety that gives a rojiy, slightly adhesive and very un- 

 satisfactory mucil&se.— Pharmaceutical Journal. 



♦■ 



ROOTS. 

 The investigation of the inner life of the Boots— their 

 structure, what they do, and how they do it-though ob- 

 viously points of the very highest importance to cultiv- 

 ators-demands special qualifications and special means, 

 neither of which are at the disposal of the ordinary gard- 

 ener. It IS unfortunate that it should be so, but it is our 

 duty to make the best of the conditions under which we 

 are obliged to work rather than lament over the impract- 

 icable. The observation of the development and growth 

 of roots so far as they can be seen by the naked eye, 

 IS a matter quite within our range, and we cannot too 

 strongly urg'e upon youug gardeners and others the nece.ss- 

 ity ot carefully e.xaminiiig and noting the nature of the 

 lOot-growth m all plants that come under their hands 



At first perhaps, they mil find that little interest is to 

 be got out of isolated observations, but when they be-m 

 to eompare the root-growth of one plant with that of 

 anotlier they mil very soon become possessed by that most 

 valuable of human faculties, the de.sire to know the reason 

 why, Iheir interest will get e.Kcited, and will increase as 

 their observations accumulate, while practical inferences 

 wdlbegm to suggest themselves, which latter must be 

 igidly tested before they are made articles of faith One 

 hint lye may be allowed to give, and that is, .as the pio- 

 b em IS a very intricate one, that they attack it not all 

 a once, but in detail. To sit down before a great leash 

 of roots and endeavour to disentangle them physically 

 and mentally-to trace what, if any, connection there is 

 between them and the branches or leaves, and so forth- 

 is a disheartening task. 



By investigating seedling plants, or watching how, when, 

 or where, and un<Ier what circumstances the roots are 

 produced there i,s a better chance of arriving speedily at 

 some usefn result The student in this as in most other 

 prol)lom8 of a similar nature, must act as the arithmetician 

 does m working out a complicated sum-reduce his mater- 

 ials to the lowest po.ssiljle denomination. This is what 

 the microscopists and the chemists do in their laboratories 

 —they endeavour to isolate each constituent, detach it 

 from Its associates, and study it in its isolated state By 

 treating each constituent in a similar manner they find 

 out what IS peculiar to each, and are very soon led on 

 to see how they act and react on each other when in 

 combination. As we h.ave said, what the microscopist can 

 do minutely, the ordinary observer can do roughly. To 

 give an illustration. One particular branch of a tree we 

 Tn, „'J''"tI'^ !!""• " '"'™™''' unhealthy, the rest rem.aiuing 

 cntwh *!,?'''"'"'. ™"'*^"*'>' "■'*'> tl^'' »Ioo'- r-iA Apri- 

 cot. A\hy that one branch? Is it that the roots corre- 



^o^:i:^^r '''''''^^'' "^ P-ea under un- 

 The reply to the question, it ,vill bo seen, turns upon 



bHween certain br.anches and certain roots. I„ the full- 



^rZTr. ^T\ ^'^ '"°««"1''«°'' «"'l intercommunication that 

 goes on between the several parts are so great and so 

 complex that the question can hardly he satisfactorily 

 answered; but if the problem were attacked before aU 

 that complexity arose, we might get a definite reply M 

 Olos,» in a treatise now before us, has gone into this quesl 

 tion of root development to an e.xtent beymi,! any of his 

 predecessors, an.l botanists who have hitherto paid little 

 attention to the subject will bo surprised to find the de- 



gree of variation there is in the mode of production of 

 what are called adventitious roots in chfferent plants, and 

 the constancy which prevails in individuals of the same 

 species. M. Olos groups these roots accordingly as they 

 spring from the nodes, beneath them, above them, around 

 them, or at a distance from them, and he indicates very 

 numerous variations in different natural orders— details 

 into the consideration ot which we cannot now follow him 

 but which clearly are of great practical interest to the 

 propagator. W'e may, however, reverting to the question 

 above raised as to the connection between the branches 

 and the roots, mention that M. Clos has been studying 

 plants of Myosurus minimus, a weed of the simplest struct- 

 ure, consisting of a root, a tuft ot leaves from which 

 uprises a single flower-stalk or several. It there is only 

 one, then there are no adventitious roots; l5ut if more 

 than one, then the number of roots is equal to that of 

 the flower-stalks, as if there were one such root to each 

 flower-stalk. It must be remembered here that M. Olos 

 IS speaking, not of the original roots derived immediately 

 from the seedling plant, but of the adventitious roots de- 

 veloped subsequently. M. Olos' paper is written from a 

 purely botanical point of view, but it is very suggestive 

 of the store of most important practical information which 

 lies ready for utilisation by those who will take the trouble 

 to do 60. — Gardeners' Chronicle, 



THE SILKWORJI DISEASE IN CHINA. 

 The gradual diminution of the exports of silk from 

 Shanghai during the last few years is a subject which 

 has been attracting interest, but of which a definite and 

 consistent explanation has been wanting. From 1S75 to 

 IS.'SO, the export of silk from the port in question varied 

 between G-S.OdO and 85,000 bales a year. Dm-ing 1881 

 and 1882, the annual quantity was only 50,000 to 55,000 

 bales; while the shipments for the season of 188^ will 

 fall short of ;i5,000 bales; this limit (which was at one 

 moment regarded as an exceptional one) not being even 

 reached, on account of the complete failure of the second 

 crop. The loss to the country is about £4,000.000 ster- 

 Ung, in addition to the diminution of customs receipts, 

 valued at about £340,000. 



These circumstances, and the facts which hnve brought 

 them about, were detailed in a comprehensive manner 

 by I\I. Paul Brunat, of Shanghai, in a letter .addressed 

 by him, ou July 12, 1883, to his Excellency Li-Hung- 

 Chung, Viceroy of Tientsin, and Minister of Oommerce 

 for the North of China. The district which is referred 

 to is specially that which exports its products from 

 Shanghai, ami which (notwithstanding its important yield 

 of silk) is of relatively small extent. M. Bruimt has com- 

 municated to a Lyons journal a copy of his interestiii" 

 statement, and explains the ignorance which has hitherto 

 been gener.al, as to the silkworm disease in China, by the 

 fact that the foreigner is kept in the dark, as far as 

 possible, by the natives of that country. The partial re- 

 duction alluiled to in 1881-82 naturally pointed to the 

 existence of disease, but it was not until the impending 

 results of the present campaign became known, that 

 microscopic research proved the existence of the malady 

 known as pehrine, in a form resembling in gravity that 

 which devastated at one time the silk-producing districts 

 of France .ami Italy. That the disease existed in China 

 in a latent form was well-known to .all concerned, but 

 it was an equally recognised fact that the hardiness of 

 the Chinese worm, and the favourable climate in which 

 it was developed, kept in check any such grave con- 

 sequences as would now s( em to have" resulted. 



Attention is called to the fact that the diminution in 

 shipments arise from no falliiig-otf in the foreign demand, 

 .as all the silk which arrives upon the Shanghai market 

 is, as a rule, disposed of for export. The cultivation of 

 mulberry trees has been on the increase, and the preli- 

 minary stops taken each sea.son have been wnth a view 

 to an augmented production. The reduced yield is at- 

 tributed to the fact that a great proportion of the worms 

 die before liaving made their cocoons, or make weak 

 cocoons, poor in their quantity of silk. This srason it 

 wouUl seem that, in certain localities, the production has 

 only been 25 jier cent of the normal croji. B.id we.iihe 

 wouM. of coLu-se, exercise a certain influccute, but th 



