396 Anniversary Address. 



disagreeable penalty not to be got rid of for many days.* It 

 is, then, in the grass that the enemy chiefly lurks ; there may 

 be, however, mites of a similar character on bushes, unable to 

 distinguish animal from vegetable food i but, in all probability, 

 the vexation is occasioned by one species only. 



Mr. Jerdon and I examined the gravel at Leader foot, to 

 ascertain if any Medicagos grew there. We found Barharea 

 vulgaris and Lepidium Smithii, but no Medicagos. The 

 absence is significant ; for no wool is washed in the Leader at 

 Earlston mill. The three Medicks {M. denticulata, M. macu- 

 lata, and M. minima^ obtained in the gravel of the Tweed 

 before, and at, and after the meeting, point to the burring- 

 machines of Galashiels, as having extracted their prickly seeds 

 from foreign wool, and then left them to float down the 

 stream, where they took root among the gravel, of which 

 seldom so much has been laid bare for many years by-past. 

 Shepherds allege that sheep disperse the seeds of furze over 

 moors, by carrying them in their fleeces till they drop into the 

 clayey soil, which the whin prefers. The wools embarked 

 from Scutari are full of the seeds cf plants, one of them being 

 actually a Medicago ; and I am told that in Dumfrieshire, 

 the wool-sorters sow the seeds extracted from the Cape and 

 Argentine wools, and raise under glass rarities unknown to 

 rural gardeners. Mr. Jerdon was the first to detect M. denti- 

 culata near his residence ; he then traced it to the Tweed, 

 whence the gravel had been brought to the walks. 



Leader-foot bridge was built in 1780. One of the arches is 

 106 feet span, and was then reckoned the largest in Britain 

 except two, one in Wales, the other at Beckley near Tanfield ; 

 the last being the largest stone-arch in Europe.f 



* In Brazil travellers are exposed to still worse annoyances from invisible 

 foes. "There is a tiny creature called the Mocuim, scarcely visible except for its 

 bright vermilion colour, which swarms all over the grass and low growth here. It 

 penetrates under the skin, so that one would suppose a red rash had broken out 

 over the body, and causes excessive itching, ending sometimes in troublesome 

 sores.- On returning from a walk it is necessary to bathe in alcohol and water, 

 in order to allay the heat and irritation produced by these little wretches. Mos- 

 quitoes are annoying, piums are vexatious, but for concentrated misery commend 

 me to the Mocuim."— 0« the Banks of the Amazon. — " Agassiz Brazil," 1868. 



t Newcastle Journal, Aug. 19 and 26, 1780. 



