The phonetic gesture of stop consonant aspiration, which is predictable in a Germanic language such as English, has been described traditionally as ranging from a ‘puff of air’ upon release of closure (Heffner 1950) to the segmental occurrence of a following voiceless glottal approximant /h/ (Trager & Smith 1951). Within the generative phonology paradigm, however, aspiration has been construed as a featural property rather than as an independent segment of its own, often casually identified simply as [+aspiration], or, following Chomsky & Halle (1968), as a positive specification resulting from ‘heightened subglottal pressure’. We take this kind of view here as well, employing a notation with superscript h ([Ch]) to indicate representations in which aspiration is encoded as an integral feature of the segment with which it is associated, while we explore the phonological realisation of aspiration in Germanic as the reflex manifestation of a spread or open glottis, an idea first advanced in the seminal work of Kim (1970), and since developed in Anderson & Ewen's treatment of ‘|O| languages’ (1987: 195–199)