80 On the Potato Grub of Tasmania. 



alluded to, which doubtless are designed to answer some 

 useful purpose to the insect. It may not be too fanciful a 

 theory to suppose that they may be of great advantage to 

 the moth in penetrating the earth, and in lifting or par- 

 tially removing such particles as would otherwise impede 

 its progress in its descent to the roots of the potatoes. This 

 must at present be received, however, as an unsupported 

 conjecture, for the writer has not yet been enabled to 

 establish the fact by ocular demonstration. 



But it is the only portion of the notes which partakes of 

 the nature of theory or conjecture — all the rest are ascertained 

 facts ; and it is to be hoped that they may not only be of 

 sufficient interest to attract the attention of the naturalist 

 and the practical farmer, but that their further considera- 

 tion and discussion may lead to the discovery of some 

 effectual means of putting a stop to the ravages of this 

 rapacious insect. 



As a precaution against the spread of the infection 

 throughout the island, all seed potatoes coming from places 

 where the insect is known to prevail should be carefully 

 sorted, and the bad ones rejected; and not only should the 

 potatoes themselves be scrutinized, but the bags or baskets 

 which contain them should be also closely examined, and, if 

 infected, burnt or cleansed. 



Any one who will be at the ti'ouble of carefully inspecting 

 a basket or sack in which infected potatoes have lain for 

 some time will find a lot of little earthy-looking excrescences 

 adhering to the inside ; — these are the cocoons of the chrysa- 

 lides covered with and concealed by earthy matter. They 

 are the media through which the evil is spread throughout 

 the country, and conveyed from one country to another; 

 and they are the pests in embryo, of which every one ought 

 to try and make a clean sweep. 



