  Four examples are given of problems that arise in the study of emission-line
stars, each of which deserves further quantitative study. (1) Archival slit
spectra of \eta Car show that epochs of low excitation have occurred regularly
in the 2020 day period of Damineli et al. since at least 1948. They last about
10 percent of the period. Earlier slit spectra (1899 -1919) suggest that the
the object was always in a low excitation state at that time. This result may
be connected with the gradual brightening of eta Car through most of the 20th
century. (2) FeII and [FeII] emission in Mira variables is probably
chromospheric. It would be important to understand how this is excited and its
relation to mass loss and dust formation in Miras. (3) Declines of RCB stars
are due to eclipses by dust clouds. At such times a rich emission line spectrum
from the outer atmosphere of the star is seen. The quantitative study of the
changes in this spectrum as more and more of the star is eclipsed should yield
important information on the extended atmosphere of these objects. (4) In deep
minima when the entire star is eclipsed, RCB stars show a broad-line emission
spectrum. The excitation of this spectrum, particularly HeI 3888A, constitutes
a puzzle. Two possible excitation mechanisms are discussed.
