THE EXTRA-NUPTIAL NECTARIES IN THE COMMON BRAKE, PTERIDIUM AQUILINUM
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چکیده
منابع مشابه
Isolation of an active glucoside in bracken fern, Pteridium aquilinum.
An active glucoside that enhanced release of histamine from rat peritoneal mast cells was isolated from a toxic fraction of bracken fern, Pteridium aquilinum, by partition column chromatography on Sephadex G-25. It was a yellowish amorphous powder on freeze-drying, readily soluble in water or ethanol, and insoluble in ether. It was hydrolysed with beta-glucosidase to release D-glucose. It was a...
متن کاملTumor induction in germ-free rats fed bracken (Pteridium aquilinum).
This study indicated that there was no significant difference in the incidence of intestinal tumors between germ-free and conventional rats fed a diet containing bracken, suggesting that gut microflora did not play a definite role in bracken tumorigenesis. However, bracken induced exclusively sarcoma but no adenocarcinoma in germ-free rats, whereas it induced predominantly adenocarcinoma in con...
متن کاملObservations on the Microanatomy of the Spermatozoid of the Bracken Fern (Pteridium aquilinum)
Salient features of structure of the spermatozoid of a fern (Pteridium aquilinum) have been determined by a combination of visual and ultraviolet microscopy, with electron microscopy of shadow-cast whole mounts and thin sections, using magnifications up to but not exceeding 50,000 diameters. Attention has been concentrated on the arrangement rather than on the internal details of the various pa...
متن کاملBracken (Pteridium aquilinum); the effect of steaming on the nutritive value of bracken hay.
The bracken fern (Pteridium aquilinum) has been known for a long time to be poisonous to cattle (Penberthy, 1893) and horses (Muller, 1897) under farm conditions. Field cases of bracken poisoning in sheep are almost unknown; the more selective feeding habits of sheep may be responsible for their apparent immunity. Bracken poisoning has been experimentally produced in cattle (Almond, I 894), hor...
متن کاملNuclear bodies in the maturing egg cell of a fern, Pteridium aquilinum.
Nuclear bodies about 250 nm in diameter, and with a strong affinity for uranium and acriflavine, appear in the nuclei of maturing egg cells of Pteridium. Many enter well-defined evaginations of the nucleus. The nuclear bodies are almost wholly digested by Pronase, but are resistant to ribonuclease and deoxyribonuclease. Radioactive labelling gives no evidence of the presence of nucleic acids, b...
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ژورنال
عنوان ژورنال: Science
سال: 1901
ISSN: 0036-8075,1095-9203
DOI: 10.1126/science.13.336.885