Abstract
A technique has been developed for detecting fungal growth on and inside the jute fiber by the differential staining of hyphae and fibers with Chlorazol Sky Blue stain. The test is also applicable to cotton. Growth inside the lumen is not a universal feature of fungal attack on jute, although nearly all the dark-colored fungi tested showed this property. which is not ordinarily lost or gained by changing external conditions of growth or by modifying the fiber. The minimum period required for lumen invasion has been found to be different for different species. Some of these fungi showed com paratively weak growth within the cotton fiber. Fungi growing within the lumen of jute seem to penetrate the fiber cell wall apparently at random, not at weak points nor through open ends. The active organisms attacking jute under different practical con ditions of damage have been found to be different. Granular bodies sometimes seen within the lumen of raw jute have been isolated and traced to a Bacillus species.