CUBBENT NOTES. 199 



me by the Editor foi* examination. To all appearance they were both 

 normal specimens of male B. quercus, and in no way approximated to 

 the structure of the female. I concluded, from my examination of 

 them with the naked eye, that the circumstances in which they were 

 placed had caused their genital structures to become accidentally en- 

 tangled ; nevertheless, I at once i)repared them for the microscope, only 

 to lind, as I expected, that both were typical males. Taking into con- 

 sideration the curious structure of the genitalia, which consist of a pair 

 of backward hooks that appear to be a modification of the Harpes, and 

 a single, very strong hook, almost at the extreme apex of the abdomen 

 (the Uncus), and all exserted, one is not surprised that some entangle- 

 ment of the ancillary organs took place under the conditions in which 

 these individuals were placed. It is well known that tlie females of 

 this si^ecies have the power of producing extraordinary sexual excite- 

 ment in the males, as is evidenced by what is termed " assembling." — 

 F. N. PiEucE, 7, The Elms, Dingle, Liverpool. Juli/ 27th, 1894. 



gURRENT NOTES. 



In concluding his paper on the Nepticulas {E.M.M., pp. 150-4) Dr. 

 Wood discusses the power of the larva? of this genus and of Lithocolletis, 

 to delay the ripening and death of the part of the leaf they are occupy- 

 ing. The leaf " shall have put on its red or yellow autumnal tint, it 

 shall even have dropped from the tree, have died and turned brown, but 

 the area in which the larva is feeding will remain alive and green, not 

 merely for days, but for weeks, provided it be not exposed to excessive 

 dryness." It has been suggested that the afflux of sap brought about 

 by the larva is the cause of this, but Dr. Wood considers that " looking 

 at one of these green patches, with its margins fading gradually into 

 the surrounding brown area, it is almost impossible to escape the con- 

 viction that, it is produced by some substance we may call a poison, or 

 a preservative, which, taken up by the sap is carried to the cells, and 

 being appropriated in its progress, gets more diluted and attenuated the 

 further it travels." Dr. Wood cannot tell us what the substance is, or 

 how it is excreted, but " the whole of its singular influence over the 

 leaf is exercised " when the larva is very young, and making its pre- 

 liminary gallery, and that some substance is then produced which beino- 

 absorbed by the vascular bundles, among which the creature is burro win<>-, 

 gets distributed to the jDarts of the leaf they supply, where it is talven 

 up and appropriated by the cells. The remarks bearing on gall-forma- 

 tion are also most interesting. The independent life of that part of the 

 oak-leaf in which the larva of N. suhbimacnlella is, long after the leaf 

 has fallen from the tree and is dried, shrunken and dead, must make as 

 great an impression on others as it did on Dr. Wood. But the essay 

 is too good to be treated like this ; those who are interested in Nature's 

 wonderful methods of work, must read the original. 



From the Daily Chronicle of July 16th, 1894, we learn that " the 

 effect of a hot summer, followed by a mild, dry winter, is ah-eady 

 beginning to be felt in Scotland in the presence of a plague of cater- 

 pillars. The pest, which is for the moment devastating various 

 districts, is the larva of the antler moth (Charaeas graminis), wliose 



