458 SECOND ANNUAL CITRUS EXHIBITION 



a semi-viscous consistency, especially where the disease is of long^ 

 standing. And if the oviter bark is subjected to as critical an exam- 

 ination, not only will minute pellicles of a gummy exudation be 

 observed, but a section of the liber, or inner bark, will present an 

 appearance quite analogous to that of the diseased rootlet. And still 

 further, the leaves themselves are found covered over with these 

 gummy pellicles. Yet it can hardly be assumed that this condition 

 is tlie effect of the presence of the scale. It seems more reasonable 

 to regard this as the cause rather than the eff'ect. In either case, the 

 tree must be regarded as seriously diseased. But the vital question 

 is. What is it ? And what are the unknown conditions to be pro- 

 vided to restore normal health and vigor? So far as the disease of 

 itself is concerned, the science of citrus posology might not inappro- 

 priately be enriched by designating this disease as the citrus scabs 

 or itch. 



Do not suggest, however, lard and sulphur as a remedy. But aside 

 from names, I presume it will be readily admitted that a disease 

 exists in the infested trees. If so, from a physiological point of view, 

 it may be asserted that any obstruction to the natural play of the 

 function of the roots, stem, branches, or leaves, must inevitably 

 result in impaired vitality and ultimate disease and premature decay, 

 unless such obstruction is removed and the tree restored to its 

 normal healthy condition. Hence, if the tree is planted in a soil 

 containing properties incompatible with its necessities for appropri- 

 ate food material, the presence and absorption of such objectionable 

 material would in due course of time work great mischief, possibly, 

 to the tree; for it is a well known fact that poisonous substances, 

 arsenic, for instance, absorbed bj^ the roots of plants, soon produces 

 decay and death, although the roots are endowed with excretory 

 powers, but it is plain to be seen that if the objectionable ingredients 

 to organic life and health were first absorbed and carried into circu- 

 lation and then expelled, this vicious product would soon accumu- 

 late about these organs to such an extent as to greatly endanger if 

 not to utterly destroy their function. 



The so-called gum disease is unquestionably due to a fungi 

 absorbed from the soil by the roots and carried into circulation by 

 the sap. This conclusion is reached mainly from the fact that it is 

 susceptible of propagation by innoculation into other trees than those 

 in which it originates. If, however, it should be discovered that the 

 scale was the cause instead of the effect of the diseased condition of 

 infested trees, it becomes no less a duty to immediately institute 

 proper treatment for their restoration to health, than if the disease 

 should arise from improper environinent or treatment. It, however, 

 would be regarded as far more satisfactory to be able to announce 

 that the presence of the scale upon the tree was the true cause of its 

 depressed and languishing condition, for there are known and simple 

 methods of entirely eradicating the parasite, whereas, should this 

 unhealthy condition arise from improper or scanty nutrition, or to 

 an undue application or withholding of water at seasonable periods, 

 the difficulty might be greatly complicated and appear almost insur- 

 mountable. 



Whatever the true cause may ultimately prove to be, however, I 

 am strongly of the opinion that there are two distinct conditions 

 underlying this difficulty, viz.: impaired leaf and root function, and 

 the primary causes must be sought through impaired nutritive 



