…each of the two side straps, chains, or ropes by which a horse is attached to a vehicle that it is pulling…
…a strand of conducting vessels extending from the stem to the base of a leaf…
…a hypothetical permanent change in the nervous system brought about by memorizing something; an engram…
…a chemical element present only in minute amounts in a particular sample or environment…
…a fossil of a footprint, trail, burrow, or other trace of an animal rather than of the animal itself…
…a historic port city on the Mississippi River in southwestern Mississippi; population 16,413 (est. 2008). The Natchez Trace, which leads from here to Nashville in Tennessee, was a 19th-century route for riverboatmen returning north from trips to New Orleans…
