Of a very different kind is the next we have to notice, the Prodromus systematis mammalium et avium of Illiger, published at Berlin in 1811, which must in its day have been a valuable little manual, and on many points it may now be consulted to advantage - the characters of the genera being admirably given, and good explanatory lists of the technical terms of ornithology furnished.
This scheme was the work of Blasius Merrem, who, in a communication to the Academy of Sciences of Berlin on the t oth December 1812, which was published in its Abhandlungen for the following year (pp. 237-259), set forth a Tentamen systematis naturalis avium, no less modestly entitled than modestly executed.
He prefixed an " Idea Systematis " to his " Expositio "; and the former, which appears to represent his real opinion, differs in arrangement very considerably from the latter.
In the same year he published his essay on comets, Conamen Novi Systematis Cometarum, which was occasioned by the appearance of the comet of 1680.
His principal works were, Conspectus systematis ornithologiae, mastozologiae, erpetologiae et amphibologiae, Ichthyologiae (Leiden, 1850), Tableau des oiseaux-mouches (Paris, 1854), Ornithologie fossile (Paris, 1858).
His Prodromus Systematis Naturalis Regni Vegetabilis was intended to embrace an arrangement and description of all known plants.
1659, 1660, 1661), and his influence is already seen on the Reformed theologian Andreas van Essen (Essenius, 1618-1677), who, in 1659, published his Systematis theologiae pars prior, the tomus secundus in 1661, but Systematis dogmatics tomus tertius et ultimus in 1665.