234 THE CANADIAN ENTOMOLOGIST. 



produced by some insect, with the Httle orifice from which it had emerged 

 very much Hke that made by Lavenm gleditscJiiceella in the thorns of the 

 Honey Locust. The Laverna, however, ^ produces no swelhng of the 

 thorn. On a journey previous to that detailed in the Heart of Africa, 

 Dr. S. had planted in Cairo seeds of an Acacia which he had gathered in 

 equatorial Africa. On his later journey these seeds had produced trees 

 which bore thorns in which were the same swellings and the hole by which 

 the insect had emerged, and the Dr. suggests the query whether the insect 

 had survived in the seed ! I or "how did it contrive to get to its tree in 

 Cairo ? " The idea is novel enough that the insect was carried in the 

 seed which survived its ravages, and in spite of them produced a tree, 

 while the insect having been planted in the seed, managed to make its 

 way through all the stages of the growth of the tree for so many years, and 

 finally emerged from its thorn. As Dr. S. states that " it also occurred in 

 several other situations " beside that at which he planted seed, a more 

 reasonable theory is that the insect was there before he planted the seed. 

 He does not inform us what sort of an insect it was. He mentions also 

 a musical sound produced by the wind blowing into the holes in the 

 thorns from which the insects had emerged. No sound, however, is pro- 

 duced by this cause in the thorns of the Glcditschia. 



I have been informed that thorns of various species of Acacia (in a 

 large sense) in Texas, New Mexico and Arizona are perforated by insect 

 borings similar to those of Laverna gledifscliiceeUa in the Honey Locust, 

 but I have not been able to procure specimens of the insect architect. 

 Prof. Sumichrast mentions similar borings in Acacias in Mexico (referred 

 to in a volume of the American Naturalist — I write from recollection and 

 cannot refer to the volume or page). These, however, like those of which 

 Mr. Belt gives such an entertaining account in " The Naturalist in 

 Nicaragua," were tenanted by ants, and according to Mr. Belt, the exca- 

 vations in the Nicaragua Acacias were made by the ants, which in return 

 for the home and shelter afforded by the thorns, furnished a standing army 

 for the tree, protecting it from depredations by other animals. Two 

 species of ants — a Mynnica very near AI. molesta Say, and a Formica 

 (F. dislocata ? Say) a:lso inhabit the thorns of Gleditschia triacanthos ; but 

 I have not been able to learn that they render any sort of service to the 

 tree, and certainly they do not excavate their own dwellings, but only 

 appropriate dead thorns that have already been excavated by the larva 

 referred to in the preceding pages — just as they might take advantage 



