Structurally parallel derivatives from a given primitive (such as Lat. TENEBR-ICUS beside TENEBR-OSUS, Fr. verd-eur beside verdure, OSp. trist-eza beside trist-ura) in the historical perspective mostly turn out to have been successive rather than simultaneous offshoots.1 As long as such formations are studied merely in word lists illustrating the ranges of the individual suffixes that go into their making, the historical sequence of events is bound to pass unnoticed or, at least, not to remain fully discernible. To shed light on the relative chronology, it is advisable to select, as an appropriate unit of inquiry, the growth of separate word families showing sufficient proliferation of derivatives. The implicit severe limitation of scope allows the explorer to focus attention on the constantly changing interrelations between the nuclear formation of each family (the primitive) and its satellites in a number of carefully selected, clearly defined cases, in which adequate documentation can be furnished and the number of unknowns in historical reconstruction is reducible to the barest minimum. These shifts are in accord with the observable semantic expansions and contractions of the radical element and the ceaselessly changing availability of formatives, which, in turn, gradually experience extensions and reductions of their original scopes, proportionate to the number of currently used derivatives in which they are represented (to the extent to which they can be individuated and detached by untutored speakers). The linguistic historian can thus work out an intricate pattern of attractions and repulsions between radical and formatives. If his interest broadens out into culture history, he is further able, in the concrete case of the Hispano-Latin lexicon, to follow the (frequently tortuous) course of an important word-family, including all its ramifications, over a period of two thousand years, with the aim of distinguishing between the services that each member of the word-family, through incessant readjustment, has lent to consecutive generations of speakers, each in search of new expressions for newly-felt needs.