Insect Carpenters. — There are several species of -what are called 

 "carpenter caterpillars," which eat galleries or tunnels in trees. In this 

 country the most common illustration of this engineering skill amongst those 

 belonging to the moth tribe is that afforded by the caterpillar of the goat 

 moth (Cossus ligniperda), which is said to have been a favoui-ite article of diet 

 among the Romans, and which tunnels its way through the willow tree. But 

 it is probably excelled in ingenuity by the caterpillar of one of the rarer 

 sphinx moths, which is known to collectors as the brown hawk (j^geria 

 aslliformis). In the interesting volume on " Insect Architecture," which was 

 published under the superintendence of the Society for the Diffusion of Useful 

 Knowledge, in 1830, the late Mr. James Rennie gives the following account of 

 what he observed with reference to the proceedings of the last-named of these 

 workers in wood. '' We observed," he remarks, '' above a dozen of them 

 during this summer (1829) in the trunk of a poplar, one side of which had been 

 stripped of its bark. It was this portion of the trunk which all the cater- 

 pillars selected for their final retreat, not one having been observed where the 

 tree was covered with bark. The ingenuity of the little architect consisted in 

 scooping its cell almost to the very surface of the wood, leaving only an 

 exterior covering of unbroken wood, as thin as writing-paper. Previously, 

 therefore, to the chrysalis making its way through this feeble barrier, it could 

 not have been suspected that an insect was lodged under the smooth wood. 

 We observed more than one of these in the act of breaking through this cover- 

 ing, within which there is besides around moveable lid of a sort of brown wax.'' 

 The great length of time which some of these boring insects may remain em- 

 bedded in wood has been amusingly illustrated by the celebrated Sir Joseph 

 Banks, and also by other gentlemen, including Mr. Ingpen, who relates in the 

 tenth volume of the " Liuna3an Transactions " that the family of a gentleman 

 at Henlow, Bedfordshire, were much terrified at seeing thousands of wasp-like 

 flies {Sires duplex) emerge from holes in the floor, large enough to admit a 

 small pencil-case. The house had been built three years, but long before that 

 time the insect carpenters had been busily at work in the spruce fir trees, 

 from which the builder had obtained his supply of wood ; and as in their case 

 " labour and rest unequal periods keep," it was only after this long interval 

 that they were enabled thus suddenly to appear in what is technically known 

 as the imago or perfect state which presents a striking contrast in its well- 

 dressed idleness to the dingy obscurity of its previously busy life of hard 

 work. — Land and Water. 



How WAS Anacharis Alsinastrum introduced to Britain ? — The intro- 

 duction of this pestilent weed was attributed, about five-and-thirty years ago, 

 when I was at Cambridge, to the scientific zeal of the Professor of Botany^ 

 after whom it was nicknamed Bahingtonia damnahilis. Whether the story 

 was true or not, nobody then held any other belief, so my old friend got the 

 (dis) -credit of it. — W., in Land and Water. 



