Rhythm is perceptually salient to the listener. This claim is central to the research project briefly described below: a large-scale investigation of listening, in which the principal issue was how listeners segment continuous speech into words. Listeners must recognize spoken utterances as a sequence of individual words, because the utterances may never previously have been heard. Indeed, list...

Norris et al. (1) presented data that "unequivocally support the idea of multilayer development of adventitious shoots from chimeral African violet leaf tissue" and concluded therefore that "adventitious shoots are of multicellular origin." Their conclusions, based on the recovery of variegated adventitious shoots regenerated from variegated leaves cultured in vitro, rely on the assumption that...