I thought that quarrels were only used in cross-bows

Yes and no by the looks of it, Rhub, depending on your interpretation of especially (i.e. 'exclusively' or 'in particular')! -

Main Entry: quar·rel
Pronunciation: 'kwor(-&)l, 'kwär(-&)l
Function: noun
Etymology: Middle English, from Old French, square-headed arrow, building stone, from (assumed) Vulgar Latin quadrellum, diminutive of Latin quadrum square
Date: 13th century
: a square-headed bolt or arrow especially for a crossbow