110 THE BIICROSCOPE. July 



SCIENCE-GOSSIP. 



Flax Retting and its Microbe. — M. V, Fribes in the lab- 

 oratory of M. S. Winogradsky has determined the cause 

 of this interesting- industrial process. The organism caus- 

 ing the separation of libers is a large bacillus 10-15 mm. 

 long and 0.8 mm. broad. It produces a large tadpole spore 

 1.8 mm. by 1.2 mm. It was obtained in pure culture by 

 cultivating the organism under anaerobic conditions on 

 boiled potatoes containing chalk. The organism does not 

 act on cellulose, it however ferments glucose, saccharose, 

 and lactose, and starch when peptone is present. Exper- 

 iments made showed that it had retting power. — Comptes 

 Rendus. 



A Disease of Melons. {Alteniaria sp.) — Late in August 

 specimens of musk-melon leaves were received at the sta- 

 tion from ]\fr. S. B. Wakeman of Saugatuck. The leaves 

 were evidently diseased, and Mr. Wakeman wrote that the 

 trouble was spreading very rapidly over his melon ground 

 notwithstanding applications of Bordeaux mixture. A 

 visit to Saugatuck confirmed Mr. Wakeman's report. Of 

 three large fields of melons, one was completely ruined, 

 and the other two showed abundant evidences of disease. 

 The trouble seemed to start at the center of the hills and 

 extend rapidly outwards. It was characterized by a wilt- 

 ing of the leaves, followed by the appearance of small yel- 

 lowish spots and blotches; these increased rapidly in size, 

 the surface of the diseased areas became marked with 

 dark, concentric rings, the tissues became dry and brittle, 

 and upon all the older spots there was a copious growth of 

 black mould distinctly visible with a lens. Microscopic 

 examination showed that the leaf-tissue in every diseased 

 spot was traversed by delicate, colorless threads, which, 

 coming to the surface either singly or in little erect tufts, 

 gave rise to short chains of large, brown, club-shaped 

 spores, provided with a long erect appendage, and serving 

 to place the fungus in the genus Alternaria. No other 

 fungus was found in connection with the trouble, and this 



