Close to sunset and sunrise bright stars like Sirius or even Canopus can be spotted with the naked eye as long as one knows the exact position in which to look. Historically, the zenith of naked-eye astronomy was the work of Tycho Brahe (1546â1601).
The egg sac, irregular in shape, about the size of a tennis ball, is often seen in the garden, suspended by silk threads. Spider bite in southern Africa: diagnosis and management: the diagnosis of spider bite, especially when the patient is unaware of having been bitten, can be difficult
Embryo Sac. or female gametophyte, the sexual generation of angiospermous plants. The embryo sac develops in the central portion of the ovule (nucellus), where the maternal macrosporocyte, as a result of meiotic division, forms four haploid cells (a tetrad of macrospores), of which one develops (the rest atrophy).ormerly, the female gametophyte of gymnosperms was also called an embryo sac; however, it differs in principle from the embryo sac in the development of a massive multicellular gametophyte body and in the formation of archegonia. Maheshwari, P. Embriologiia pokrytosemennykh. Moscow, 1957.