stated that the progress eastward of the insect from its home in 

 the Rocky Mountains was at the rate of about seventy miles per 

 annum, and at that rate it would reach the Atlantic Coast in 1878. 



In the January number for this year of '• Science Gossip," I find 

 a most interesting letter on the subject, written by a gentleman 

 apparently a German, under the initials of " Fr. H." from the 

 " State of Illinois." It appears that the pest appeared in that 

 district in 1865 : "In 1868 Indiana was visited ; in 1870 Ohio 

 and the confines of Canada were reached, also portions of Pensyl- 

 vania and Xew York, and its entrance into Massachusetts was 

 notified." 



He adds that before long we shall hear of them swarming in the 

 streets of Boston and Xew York, and then their passage across 

 the Atlantic is a mere question of time. 



The ravages of this insect are so gi-eat, that where it exists it 

 threatens to di-ive the potato out of cultivation, so that before 

 long, if we wish to avert a potato famine, it will be necessary to 

 pass a Contagious Diseases (Vegetables) Act, and place the 

 American sacks of the esculent in Quarantine. 



It is undoubtedly a very serious question. If the insect ari'ives 

 in England it will probably be unaccompanied by the insects 

 which prey upon it. 



In America it has numerous enemies. Mr. Riley says that it is 

 preyed upon by one Dijjteron, four Ladybirds, five other species 

 of Beetles, and four Bugs ; and also that two species of Beetles, 

 which are destructive to the potato, have this redeeming quality, 

 that they occasionaly eat the pest under consideration, which is 

 commonly called the " Colorado Potato Beetle." 



Such numerous enemies have no doubt kept the beetle in check 

 in the Rocky Mountains, and no doubt the balance of nature 

 remained undisturbed so long as it fed on the wild Solanum ros- 

 tratvm — the plant and the insect throve together. But it is 

 far diiferent now it has attacked the Potato, the Tomato, and the 

 Ground Cherry. These plants had all enemies enough to contend 

 with before, and appear in most instances to liave completely suc- 

 cumbed to the new pest, as the cattle of tliis country did recently 

 when exposed to tlie contagion of the Rinderpest. 



It is interesting to remark that a very closely allied species of 

 the same genus, viz., Donjphora jimcfa (Germar), feeding also on 

 a plant of the' potato genus, viz., Solanum caroUnense, Linn., has 



