38 THE CELL MEMBEANE OF EUMYCETES. 



dextran, which is turned blue by iodosulphuric acid and has 

 been detected in several fungi by E. Wintehstein (IV.). 

 According to an observation made by the same worker (HI.)? 

 true hemicellulose in the sense applied to the term by E. Schulze, 

 also seems to occur in fungi. Two mvicinous carbohydrates, 

 known as mycetide and viscosin, but not yet closely examined, 

 are found in various mushrooms, according to a report of 

 Boudier's cited by A. and Tii. Husemann (I.). The former of 

 these substances presumably resembles the gums, whilst the 

 other probably is closely allied, chemically speaking, to the 

 mucilage found in linseed and Plantcujo PsijUhnii L. According 

 to an analysis made by J. L. Keller and reported by the Huse- 

 manns, pectose has been isolated from Fouh-ling. 



Still undetermined is the chemical character of the substance 

 giving the blue iodine reaction observed by Feiedrich Hoffmann 

 and by Paul Lindner (VIII.) in the case of the phlegmated 

 hyphse of Demafimn pnllulans and the membrane of the spores 

 and sporogenic cells of ScMzosaccharomyces odosporus, and also by 

 E. Cramer (III.) on the conidia of PenicilHnm r/Jaucuvi. The 

 substance in question is certainly not starch, but is possibly an 

 isolichenin. Moreover, the blue reaction with iodine solution is 

 by no means a rarity, being observed, for example, on the apices 

 of the asci of many Pyrenomyretes and Discomycetes; whilst similar 

 obsei'vations have been made by 0. E. R. Zimmermann (II.) 

 in different species of Mucor. The red mould (of the genus 

 Ft(sarivvi) occurring as red spots and stripes on barley and malt, 

 where it was first observed by C. G. Matthews (I.) and afterwards 

 by Carl Klein (I.), excretes— through the swelling of the outer 

 layer of the cell membrane — a mucilage which is coloured violet 

 by iodine. 



After employing the usual treatment for the determination 

 of crude fibre, C. Taneet (I.) found, in the thallus of Aspergillus 

 m'ger, the hard mycelium of Claviceps imrpurea, the corpus of 

 Polyporits ofyct7ialis and Bohtus echdts, and in yeast, a carbo- 

 hydrate which he named fongose and to which he ascribed the 



formula (C6H^o05)6- 



The presence of a carbohydrate of the pentosan group 

 (C^Hj^O^) has been detected in seveial species of fungi by 

 Dreyfuss (I.). The cell membrane preparations made by 

 WiNTEiiSTEiN (II.) must also have contained pentosans, since 

 they furnished i to 2 per cent, of furfuiol when distilled with 

 hydrochloric acid. 



Basing on the results of microchemical i-eactions performed 

 with vai'ious colouring matters, Mangin (IV.) thought himself 

 justified in assuming that callose — a carbohydrate allied to the 

 pectins and discovered by him in different phanerogams — also 

 occurs, and indeed forms the chief constituent material in the 

 cell membrane of fungi, and of the Ascomycete^ in paiticular. 



