September i, 18S5.] THE TROPICAL AGRICULTURIST. 



tSj 



in^itance to the mature aphide and the work of the speedy 

 decay of the^leaf is accomplished by the larva. Briefly 

 I mean to assert, that, supposing no physiol or chemical 

 connection can be traced between the fungoid deposit 

 and the insect, and although the former were altogether 

 removed, a still mora formidable enemy would 

 exist in the shape of its unfortunate host and 

 its larv<B, 



• You said, sir, in your footnote to mj' letter, that 

 I ought to have read Marshall Ward's reports before 

 discussing such a question, and doul>tless I would have 

 done so had they been within my reach ; but probably 

 had I seen these reports bffore 1 was induced to study 

 this insect's life, I should not have devoted any 

 attention to the subject at all, and what you simply 

 mean, I take it to be, is that we should 

 ■' Rather bear the ills we have 

 Thau fly to others which we know not of." 



I did not, by any means, intend my letter to have 

 the effects of a hand-grenade thrown among my 

 fellow planters but as a harbinger of hope, 

 for the tail of a snake is more dreaded than its 

 head when the latter is hidden from us. So 

 it is with leaf-disease. If however we should happen 

 to stumble upon the root of the evil, surely we can look 

 at it straight in the face with cheerful fortitude know- 

 ing that we have soiue hope of applying an effectual 

 remedy. But if I have done wrong in unreservedly 

 offering to the public the results of my researches, I 

 shall say no more about it. 



I am not aware what insect Marshall Ward may have 

 referred to. There are no less than six different kinds 

 of insects which I hare found existing on coffee leaves 

 alone, but the one which I have particularly alluded 

 to is the transparent aphide which is the only one that 

 penetrates beneath the epidermis. 



I a^k no one to accept of my convictions before test- 

 ing the accuracy of my assertions. Agricultural in- 

 stinct, in spite of systems, classifications and scientific 

 frowns, has, before now, fathomed facts, while soieutiats 

 were hopelessly adrift on the undulating waves of 

 theory. If my intuition is found to he correct, it must 

 be admitted that there is little hope of the disease 

 dying out 60 long a j a single aphide remains alive. It 

 may be less virulent after a previous attack, as it often 

 is, or it may apparently disappear for a season until a 

 fresh brood of insects spring up. On the other hand, 

 if my theory be altogether groundless, 



" Behold ! the jaws of darkness to devour it up." 



But the remedy I have suguested, so far as I am able 

 to judge from the trees on which I have tiied it, is, I 

 think, the most (^fffctual whether the effect* are due 

 to a fungus or to the insect. OBERON. 



P-^- — On Second thcughta I consider it is my duty, 

 Mr. Editor, to send jou the enclosed sample leaf taken 

 from 18 months old cinchona (officinalis) planted 

 amonast the coffee to enable you to judge of facts for 

 yourself and give publicity to them or not as you may 

 think best. This is the effect of the same identical 

 insect. You will be able to perceive the enormous 

 holes punctured by these minute creatures at the base 

 of the veins just as they do with Coffee leaves, and you 

 may possibly be able to find some of the transparent 

 aphid* 3 still remaining in the holes. These were full 

 of them before I pressid the leaf last ui^ht. The fun- 

 gus however does not appear to be yet ripe or it may, 

 in this case, assume a different nature. 



It was only quite recently that I noticed the insect 

 attacks cinchona as well as eotfee, and I sinipy .^tard 

 appalled to conternphite what it may not do to tea 

 planted among cuffoe or on land where coffee had pre- 

 viously been. 



Whatever yon may think, sir, it is full time that 

 this insect was being looked after. 



I am not inclined to enter into any such nonsenae 

 as a discussion about the creature's bodily members 

 and what not. I have pointed out your enemy and 

 shown its powers of destruction. Go and attack it 

 at once or you will only be able to withstand it ultim- 

 ately with rich soil and abundant manure of the 

 very best quality. 0. 



[The leaf sent by " Oheron " has got mislaid : if 

 he sends another, or better, a few leaves in a match- 

 box with the insects, we shall have them examined ; 

 but ''O." is conjuring up a big spectre on a very 

 slender foundation. — Ed.] 



HELOPELTIS AND ARSENIC : A WARNING. 



Dear Sir, — Seeing no one else has done so, allow 

 me to sound a note of warning, s) that your cor- 

 respondent may hear it, who is going to extermin- 

 ate (?) helopeltis with arsenic. This poison is not to 

 be trifled with : it is more than probable that the 

 insect he hopes to destroy, having abundance of 

 natural food, will take no notice of the trap ; but 

 it is quite likely that many other insects, even birds, 

 rats and sqairrels, may, and no one can tell where 

 the mischief will end. I have known birds to die 

 from eating poisoned insects, and cats to die from 

 eating the poisoned birds. I have known many cases 

 of domestic fowls dying from the same cause, dogs 

 and cats lost from eating poisoned mice and rats. 

 1 once lost a much valued terrier from eating a 

 poisoned rat. It must be remembered that arsenic 

 nerer loses its destructive power over life : much 

 suffering and lo.ss amongst our pets and poultry 

 could, I expect, be traced to poison carelessly used, 

 particularly to that pernicious stuff, phosphorus, so gen- 

 erally used to destroy mice &c. and which is supposed 

 to be harmless to most other creatures. ZOOZOO. 



COFFEE-LEAF DISEASE. 



Dear Sir, — If I have trodden on our good friend 

 " Oberon " 's toes in any manner I apologize by assurance 

 that it was quite unintentional on my part. 



I take it "Oleroii" and "Puck" are one in doubt- 

 ing whether coffee leaf-dise.ase is propagated by the 

 orange-colored fungus dubbed "spores." " Oberon " 'a 

 discovery of an almost transparent aphide (should 

 it not be aphis?) will be an important factor in 

 future investigations : so, like a good man, Mr. Editor, 

 do not choke us off by saying, the spores do, as 

 as a matter of fact, enter the leaf, but admit the 

 possibdity of the spores being the fff'ect and not the 

 cause. I, .at least, must hold this view until it is 

 explained how a thing said to be without the power 

 of bcomotion can yet tiavel at its will. PUCK. 



["That the spores rn'er the .stomata and that sub- 

 sequently the inycelmin s-pre.ads through the cells and 

 feeds on the lileblood of the leaves, are facts as 

 certain as that the atmosphere consists of hydrogen, 

 oxygen and nitrogen in cerlain proportions. To 

 trace the fungus to insect oriuin would be as scienti- 

 fic as the ide.i, attrihiiled to Thwailes, but which he 

 indignantly repudiated, that I he disease was in the 

 juices of the plant, or th? outrageous rubbisli of that 

 emptiest of collapsed windbigs, Moutclar, that the 

 fu )gi deve'oped from ulcers in the suljstance 

 of the stem ! A gentleman to whom true aeience 

 and careful observation are dear is lO troubled 

 about •' Oberon" 's aherr-itions, that he sends us a 

 copy of Marshal! Ward's ,'atest report to be 

 forwarded to that writer. 'I he scientist states : — 



"Such ignorance I could scarcely have supposed possible 

 after all that has been rlone in tlie matter. I was 

 glad to see your deriiU'd edit<»rial comments; but iu 

 my opinion you should not give such misleading nonsense 

 a place in your columns. It is everybody's interest — even 

 the writer's— to sink such rubbish in oblivion. As I have 

 before said to you, I think, when a writer professes to have 



