. Lectures on the evolution of plants. Botany; Plants. SEED PLANTS 165. goniatse, and the egg thereupon begins to grow and develops into the embryo-sporophyte, while the sur- rounding cells of the gametophj'te become filled with food-materials and are known as the " endosperm." The wall of the sporan- gium now hardens, while the outer tissues of the integument become pulpy^ so that the ripened seed looks very much like the fleshy fruit of a plum or cherry. That the Cycads represent a very an- cient type is shown by their fossil re- mains, which indicate that during the Mes- ozoic age
Central Historic Books / Alamy Stock Photo
Image ID: PG1XYF
This image is a public domain image, which means either that copyright has expired in the image or the copyright holder has waived their copyright. Alamy charges you a fee for access to the high resolution copy of the image.