68 HOPS. [1899 



authenticated record; also it might chance that where A. rhombens is 

 found, as, for instance, at locahties in Sherwood Forest, or in the New 

 Forest, &c., in decaijed icond, that this, if infested, might possibly be 

 used serviceable in potthig-plants, as Maidenhair Ferns, for instance, 

 that are especially subject to weevil attack. 



The old idea that Rape-cake is beneficial by means of the Wireworms feeding 

 on it until they burst was again alluded to. Relatively to this point, I am 

 able to say that, in order to be certain that the idea was wholly erroneous, 

 I have fed good numbers of Wireworms \vholly on the ordinary Rape-cake, 

 and also on the Indian or Kurrachee cake, formed of Mustard seed, for 

 weeks together, and found that absolutely and certainly no such results 

 followed. In each case the cake was prepared by being pounded into 

 small lumps and dust, and moistened with water. A far larger supply 

 was given than was requisite for food of the numbers of Wireworms 

 experimented with, and it was placed (each kind separately) in bowls 

 or open vessels in the open air. The Wireworms placed on the 

 ordinary Rape-cake went into it at once, and there they fed (or to all 

 appearance fed) for three weeks or more. After this, as there did not 

 appear to be any use in further observation, I discontinued the experi- 

 ment, but certainly none of the Wireworms burst during the above 

 period. Some of them died, and I found that then, or when a 

 specimen had stiffened itself in examination, that it was apt to be 

 cracked across in handling, and the white contents burst out at the 

 fracture. This circumstance may have given rise to the popular 

 belief. 



The Wireworms placed on the Mustard-cake appeared very uneasy 

 from the stinging effects of the recently moistened Mustard, and I 

 furnished them with a little bit of turf, and on about the fourth day 

 afterwards they began to transfer themselves to the cake, where they 

 (presumably) fed for about a fortnight, all of them continuing well and 

 thriving. After this I found many dead or dying, and, though I gave 

 them fresh turf and pieces of Potato and Turnip in addition to the 

 cake, they all died ; but none of them (any more than any of those fed 

 on common Rape-cake) died of bursting. The benefit derived from 

 Rape-cake dressings as an antidote to Wireworm mischief is in part 

 from its effect as a manurial stimulant in supporting the plants under 

 attack, and partly also from attracting the "worms" away from the 

 plants to a food to which they are excessively partial ; but we have no 

 authenticated record of such inflation taking place from the food as to 

 cause bursting. 



Effect on Wireworms of Castor-oil seed cake, Rape-cake, and also of 

 absence of food. — The following details of experiments carried on during 

 a period of three months by Dr. Bernard Dyer (Laboratory, 17, Great 

 Tower Street, London, E.G.), relatively to effect of Castor-oil seed cake 



