65 

 132— THE ASPHYXIATOR. 



The machine previously mentioned No. I, Vol. II, p. 3 — has now 



been introduced to the Colony and is doing good work in extermina- 



;king the common pest known to our cultivators as the " Parasol Ant" 



Jy or {CEcodama cepfalotes) and the sanction of the Government has been 



/obtained for its use by the Wardens in several of our country districts. 

 Instructions for using the machine have been issued from this office 

 in the form of a Circular Note which will be found at page 5Q. 



133.-DISEASE. 



When we speak of the diseases of plants it is to be understood, 

 that disease means, an unnatural, unhealthy, or sickly condition 

 induced by some cause. 



The causes which produce disease in plants are perhaps as various 

 as those which produce disease in the animal kingdom, but it must 

 be accepted, as in that kingdom, that all disease arises from some 

 known or unknown cause. 



We frequently hear the attacks of parasites, animal and as well 

 as vegetable, spoken of as disease, if they induce such a condition of 

 health from their attack, as to set up enfeeblement of the tissue and 

 ultimate destruction, but if on the other hand these parasites are 

 merely common feeders upon already enfeebled tissue, then it is 

 considered that to call such a condition, disease, and refer it to the 

 attack of the organism, would be erroneous. In the latter case they 

 are saprophytes, but in the former, parasites, or feeders on healthy 

 tissue. 



It is known to be an accepted theory with some, that the attack 

 ot animal organisms or plants is always the forerunner of disease 

 appearing in some classes, and in like manner others, take an attack 

 of vegetable parasites, such as the lower orders of fungi, to be disease. 



A constant observation of the factors operating to bring about 

 conclusions in these matters for over thirty years in temperate and 

 tropical regions, leads me to think that the attack of insects may as 

 certainly sap the vitality of a plant, as the attack of a cow upon a 

 bundle of grass will destroy that plant — but it is evident that we 

 cannot call the attack of the cow on the grass a disease, and reasoning 

 by analogy ; neither can you call the attack of the insect, disease. 



If you bring a plant from a cold and dry climate to one which is 

 warm and moist, the very surroundings of that plant are unsuitable 



