We have detected an absorption feature at the location of the Wing-Ford band near 9916A in high-quality CCD spectra (S/N > 150 A^-1^) of five elliptical galaxies taken with the Cerro Tololo 4m RC spectrograph. The mean strength measured is 0.013 mag +/- 0.001 (1σ of the mean) and individual galaxy strengths have 1σ errors of order 0.002 mag. The (3-4) band of the δ system of TiO with band head at 9986A has also been detected. This suggests that the observed Wing-Ford feature is affected by the (2-3) band of the δ system of TiO at 9899A, present in late giants, and is not exclusively due to the FeH molecule strong in late M dwarfs. Confrontation with isochrone models of Whitford, indicates incompatibility with a coeval model based on a power-law initial mass function (IMF) for any value of its exponent. This incompatibility may be the result of uncertainties associated with the models or may imply a nonmonotonic IMF which would increase the giant dominancy of the integrated light near l micron. These results very likely exclude dwarf- enriched models.
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Hardy et al. (1988) studied this question.