BACKGROUND AND AIMS Mycorrhizal specialization has been shown to limit recruitment capacity in orchids, but an increasing number of orchids are being documented as invasive or weed-like. The reasons for this proliferation were examined by investigating mycorrhizal fungi and edaphic correlates of Microtis media, an Australian terrestrial orchid that is an aggressive ecosystem and horticultural w...

The ability of sponges to feed in diverse (including oligotrophic) ecosystems significantly contributes to their ubiquitous aquatic distribution. It was hypothesized that sponges that harbour small amounts of symbiotic bacteria in their mass feed mainly on particulate organic matter (POM). We examined the nearly symbiont-free (by microscopic observation) filter-feeding Red Sea sponge Negombata ...

most common source of metastasis to the gastrointestinal tract, the features of these metastases as viewed by magnifica− tion endoscopy have not been reported. A 77−year−old man whose right great toe had been amputated 3 years previously due to malignant melanoma underwent endoscopy because he was anemic. Mul− tiple black, depressed lesions (1± 5 mm in diameter) with a “bull’s eye“ appearance w...