343 



fices to say here that the cutting instrument proper resembles a sur- 

 geon's lancet, the two edges of which are armed with a saw, and that 

 the modification of the typical Lepidopterous ovipositor is in the same 

 lines as shown by us in Pronuba and Prodoxus. The sawing or pierc- 

 ing ovipositor is more common in Microlepidoptera than is generally 

 supposed. 



ALTEEATIONS IN THE FOEM OF PLANTS DUE TO COCCID^. 



On this subject Mr. W. M. Maskell has an interesting article in the 

 November, 1890, number of the Entomologists Monthly Magazine. After 

 stating that the great majority of Coccids do not materially alter the 

 form of the plants they infest, he discusses briefly the few species that 

 are known as gall makers. The usual explanation that these galls are 

 produced "by irritation of the tissue consequent on the suction of the 

 l)lant juices through the rostral tubes of the insect" Mr. Maskell thinks 

 insufficient, for the reason that, since all Coccids work in precisely the 

 same way, the absence of galls in the majority of species is not ac- 

 counted for. More space is devoted to the "burrowing" Coccids, i. e., 

 those species which produce on the leaves or twigs they infest shal- 

 lower or deeper cavities, until we come to such species as are more or 

 less completely buried in the substance of the leaf or the bark. Since 

 most of these burrowing species are apodous, the legs can play no part 

 in producing the excavations, nor is it known that Coccids secrete any 

 acrid or acid fluid. The explanation that the excavations " are merely 

 due to the increasing growth of the insect, which, passively as it were, 

 prevents the growth of the plant from filling up its usual form," would 

 seem to be most plausible if the excavations occurred only on young 

 and soft leaves or twigs; but since they occur also on the harder and 

 older leaves of bark, Mr. Maskell is inclined to admit that " the action 

 of the Coccid is not merely one of passive obstruction but one of active 

 excavation." We should argue here as we have done in discussing the 

 same subject in Aphids, which produce galls or other deformations of 

 plant tissue, that a poisonous principle must exist, however difficult to 

 detect. 



INSECT INJURY TO BARREL STAVES. 



An interesting case is reported in the September number of the Eew 

 Bulletin, in which some barrels which were shipped to Calcutta from the 

 Indian store department were found on their arrival at Calcutta to have 

 been spoiled, owing to the work of some insect in the staves. A question 

 arose as to whether the casks were unsound when they were shipped 

 from England, or whether they were attacked on board ship on the 

 voyage out, and we can readily imagine that litigation would have 

 arisen had this been a private matter rather than one of government 

 concern. The circumstance was investigated by Mr. W. F. H. Bland- 

 ford, lecturer on entomology at the Indian Civil Engineering College, 



