rature accessible to English readers--was scant indeed.
Cooke's translation of Rostafinski, in so far as concerned the species
of Great Britain, was practically all there was to be consulted in
English.

In 1892 appeared in London Massee's _Monograph of the Myxogastres_, and
two years later in the same world's centre the trustees of the British
Museum brought out Lister's _Mycetozoa_. Although these two English
works both claim revision of the entire group under discussion, the
latter paying special attention to American forms, nevertheless there
still seems place for a less pretentious volume which for American
students shall present succinct descriptions of North American species
only. The material basis of the present work consists of collections now
in the herbarium of the State University of Iowa. In accumulating the
material the author has had the generous assistance of botanists in all
parts of the country, from Alaska to Panama, and the geographical
distribution is in most cases authenticated by specimens from the
localities named. The descriptions, in case of species represented in
Europe, are based upon those of European authors; for forms first
described in this country, the original descriptions have been
consulted. A bibliography follows this preface.

In reference to the omnipresent vexed question of nomenclature, a word
is perhaps necessary. De Candolle's rule, "The first authentic specific
name published under the genus in which the species now stands," may be
true philosophy, but it is certainly an open question how that rule
shall be applied. If an author recognized and defined a given species in
times past, and, in accordance with views then held, assigned the
species to a particular genus, common honesty, it would seem, would
require that his work be recognized. To assume that any later writer who
may choose to set to familiar genera limits unknown before shall thereby
be empowered to write all species so displaced his own, as if, forsooth,
now for the first time in the history of science published or described,
is not only absolutely and inexcusably misleading, but actually
increases by just so much the amount of _debris_ with which the taxonomy
of the subject is already cumbered.

In face of a work so painstaking and voluminous as that of Rostafinski,
and in view of the almost universal confusion that preceded him, it
would seem idle to change for reasons purely technical the nomenclature
which