Kjöbenhavn, Bianco Luno, 1842 a. 1845. 4to. Bound in one contemp. halfcalf, spine gilt. A small tear to backhinge at lower compartment of spine. IV,76 pp. and 3 double-page, folded lithographed plates with many figs. + XIV,88 pp. and 2 double-apge lithographed plates with many figs. Light browning to the last leaves of the second work.
The scarce first edition of the work in which Steenstrup describes his discovery of the principle of 'ALTERNATION OF GENERATIONS'', sexual and asexual in plants and animals.
"(Steenstrup) showed that certain animals produce offspring which never resemble them but which, on the other hand, bring forth progeny which return in form and nature to their grandparents or more distant ancestors." (Garrison & Morton No 217). A German translation was published the same year, and an English in 1845. Norman 2009 (German translation).
"The second major publication - (the first dealing with geology) - of 1842 was "Om Forplantning og Udvikling gjennem vexlende Generationsrækker...", (the work offered), Steenstrup's comprehensive presentation of the form of reproduction that he called 'alternation of generations', that is, the alternation of asexual and sexual reproduction, or metagenesis. This phenomenon had previously been described by Chamisso, but Steenstrup included a greater number of observations, based on a significantly wider range of subjects, and provided an importent chapter on its meaning. Steenstrup's growing reputation, won him an appointment as professor of zoology at the University of Copenhagen, where he tought from 1846 until 1885."(DSB XII, p. 9).