AMB 



29 



AMB 



usually attains the size of a large hen's I 

 egg, has a rugged, ichorous, and even 

 mouldy surface, smelling strong and of- 

 fensively. The fibrous roots, besides 

 being generally thickened, are distorted 

 and monstrous from swellings, which 

 appear throughout their length, appa- 

 rently arising from an elTort of nature to 



Another general result of experience 

 is, that the ambury is most frequently 

 observed in dry seasons. This is also 

 what might be anticipated, for insects 

 that inhabit the earth just beneath 

 its surfice, are always restricted and 

 checked in their movements by its 

 abounding in moisture. Moreover, the 



form receptacles for the sap, deprived ; plants actually affected by the ambury, 

 as it is of its natural spissation in the ' are more able to contend against the in- 

 leaves. These swellings do not seem jury inflicted by the larva of tlie weevil, 

 to arise immediatp|y I'rom the attacks by the same copious supply. 



of the weevil, for I have never observ- | 

 ed them containing its larva. 



In wet seasons, I have, in a very few 

 instances, known an infected cabbage 



Mr. Marshall very correctly describes j plant produce fresh healthy roots above 



the form which this disease assumes 

 ^^hen it attacks the turnip. It is a large 

 excrescence appearing below the bulb, 

 growing to the size of both hands, and, 

 as soon as the hard weather sets in, or 

 it is, by its own nature, brought to ma- 

 turity, becoming putrid and smelling 

 very offensively. 



These distortions manifest themselves 

 very early in the turnip's growth, even 

 before the rough leaf is much developed. 

 Observation seems to have ascertained. 



the swelling of the ambury. Mr. Smith, 

 gardener to M. Bell, Esq., of Woolsing- 

 ton, in Northumberland, expresses his 

 conviction, after several years' expe- 

 rience, that charcoal-dust spread about 

 half an inch deep upon the surface, 

 and just mixed with it by the point of a 

 spade, effectually prevents the occur- 

 rence of this disease. That this would 

 be the case we might have surmised 

 from analogy, for charcoal-dust is offen- 

 sive to many insects, and is one of the 



that if the bulbs have attained the size of j most powerful preventives of piitrefac- 

 a walnut unaffected, they do not subse- tion known. Soot, I have reason to 

 quently become diseased. The maggot : believe, from a slight experience, is 

 found in the turnip ambury is the larva I as effectual as charcoal-dust. Judging 

 ofa weevil called Curculiopleurostigma. j from theoretical reasons, we might con- 

 " I have bred this species of weevil," 

 says Mr. Kirhy, " from the knob-like 

 palls on turnips called the ambury, and 

 I have little doubt that the same in- 

 sects, or a species allied to them, cause 

 the clubbing of the roots of cabbages." 

 Marsham describes the parent as a 

 coleopterous insect of a dusky black 



elude that it would be more specifical ; 

 for, in addition to its being, like char- 

 coal, finely divided carbon, it contains 

 sulphur, to which insects also have an 

 antipathy. 



I have a strong opinion that a slight 

 dressing of the surface soil with a little 

 of the dry hydro-sulphuret of lime, that 



colour, with the breast spotted with ' may now be obtained so readily from 

 white, and the length of the body one the gas-works, would prevent the oc- 



line and two-thirds. The general ex 

 perience of all the farmers and garden- 

 ers with whom I have conversed upon 

 the subject, testifies that the ambury 

 of the turnip and cabbage usually at- 

 tacks these crops when grown for suc- 

 cessive years on the same soil. This 

 19 precisely what might be expected, 

 for where the parent insect always de- 

 posits her eggs, some of these embryo 

 ravagers are to be expected. That they 

 never attack the plants upon a fresh 

 site is not asserted ; Mr. Marshall's 

 etatement is evidence to the contrary ; 

 but it is advanced that the obnoxious 

 weevil is most frequently to be observed 

 in soils where the turnip or cabbage has 

 recently and repeatedly been cultivated. 



currence of the disease by driving the 

 weevils from the soil. It would proba- 

 bly as effectually banish the turnip fly or 

 flea, if sprinkled over the surface im- 

 mediately after the seed is sown, I 

 entertain this opinion of its efficacy io 

 preventing the occurrence of the am- 

 bury, from an instance when it was ap- 

 plied to some brocoli,ignorantly endea- 

 voured to be produced in successive 

 crops on the same plot. These had in- 

 variably failed from the occurrence of 

 the amburv, but the brocoli was now 

 uninfected. The only cause for this 

 escape that I could trace was, that, just 

 previously to planting, a little of the 

 hydro-sulphuret of lime had been dug 

 in. This is a very fetid powerful com- 



