. Foundations of Botany. Botany. TYPES OF CRYPTOGAMS; THALLOPHYTKS 243 the division of the protoplasm and formation of a partition of cellulose in a kind of pond-scum are shown, but the nucleus and its changes are not represented. Another kind of reproduction, namely by conjugation, is found in Spirogyra. This process in its simplest form is found in such unicellular plants as the desmids It? (Fig. 178). Two cells (apparently precisely alike) come in contact, z undergo a thinning-down or absorp- tive process in the cell-walls at the point of contact, and finally blend z their protoplasmic cell
. Foundations of Botany. Botany. TYPES OF CRYPTOGAMS; THALLOPHYTKS 243 the division of the protoplasm and formation of a partition of cellulose in a kind of pond-scum are shown, but the nucleus and its changes are not represented. Another kind of reproduction, namely by conjugation, is found in Spirogyra. This process in its simplest form is found in such unicellular plants as the desmids It? (Fig. 178). Two cells (apparently precisely alike) come in contact, z undergo a thinning-down or absorp- tive process in the cell-walls at the point of contact, and finally blend z their protoplasmic cell-contents, as shown in the figure, to form a mass known as a spore, or more accu- rately a zygospore, from which, after A. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Bergen, Joseph Y. (Joseph Young), 1851-1917. Boston, Ginn & company
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1901
