[Frankfurt am Main, 1968]. Handwritten on rectos (and one verso) of two uniform, loose, ruled leaves (21.0 x 14.9 cm), and two leaves (30.0 x 21.0 cm) of the same text, as typed manuscript.

The original manuscript of Robert Mertens's publication titled Bemerkungen zur "Normalentwicklung" des Kaukasus-Salamanders, published in Samamanda, volume 4, pp. 44-45. Professor Robert Mertens (1894-1975) was one of Germany's foremost zoologists and herpetologists during the 20th century. In 1919, after completing his studies, he became first assistant of the Senckenberg Museum in Frankfurt am Main. In 1920 he became curator for herpetology, and in 1934 head of the zoological section. Finally, in 1947 he became director. Mertens was not only one of the foremost herpetologists of his time, but also one of the most productive of all time. This manuscript reveals some of his methodology. First he carefully wrote a draft in blue ink, usually with few original additions and corrections, then he made new corrections and additions in pencil. Leaf sides are separately numbered. The typed manuscript has a few additional corrections in Mertens's hand. All leaves in very good condition. Adler I, pp. 98-99; Schirner, 708.