THE DISCOVERY OF TYLOSE FORMATION BY A VIENNESE LADY IN 1845

Introduction This fascinating detective story began a few years ago when I was working on a chapter entitled 'Dysfunction in the flow of food' for a fivevolume treatise on plant pathology (Zimmermann & McDonough, 1978). Tyloses, occasionally regarded as causing interruption of water flow in the xylem, are more likely the result of cessation of water conduction (Klein, 1923). During a search for older literature on tyloses I came across the paper of Wieler (1888), and found in the same volume an article by Prael (1888). The latter contained a very peculiar paragraph. Freely translated, it reads as follows: 'Tyloses formation has been explained by an anonymous paper in 1845. His (correctly her) observations indicated that tyloses were outgrowths, through the pits, of neighboring wood parenchyma cells. This was generally accepted until it was questioned by Bohm who maintained that 'those peculiar structures are the result of accumulation of cytoplasm between the lamellae of the vessel wall, whose innermost layer grows into a tylosis.' However, Reess (1868) and Unger (1867) defended the earlier view successfully.' The German grammar (here translated by 'his' and 'her') implies that the author was a lady. I immediately went to the library of the Harvard University Herbaria to look up Volume 3 of the 'Botanische Zeitung' where, indeed, I found an anonymous paper, published in two parts in two successive issues. Interestingly, the wording 'von einem Ungenannten' (by an anonymous author) implies a male author. My fascination increased as I read the text: here was such a comprehensive description of tyloses, based on such careful observations that many later papers seemed redundant. Who was the author of this? After a long search I finally came across the answer in the . 'Physiological Plant Anatomy' of Haberlandt (1914) who begins his section on tyloses, 'These intrusive vesicles, the development of which was first studied and explained by Hermine von Reichenbach, are known as tyloses.' In the bibliography Haberlandt cites the paper under the name