Elementary botany . d in figures 132-137. CHAPTER XV. VAUCHERIA. 299. The plant vaucheria we remember from our study inan earlier chapter. It usually occurs in dense mats floatingon the water or lying on damp soil. The texture and feeling ofthese mats remind one of felt,and the species are sometimes calledthe green felts. The branchedthreads are continuous, that is thereare no cross walls in the vegetativethreads. This plant multiplies it-self in several ways which wouldbe too tedious to detail here. Butwhen fresh bright green mats can beobtained they should be placed ina large vessel of water
Elementary botany . d in figures 132-137. CHAPTER XV. VAUCHERIA. 299. The plant vaucheria we remember from our study inan earlier chapter. It usually occurs in dense mats floatingon the water or lying on damp soil. The texture and feeling ofthese mats remind one of felt,and the species are sometimes calledthe green felts. The branchedthreads are continuous, that is thereare no cross walls in the vegetativethreads. This plant multiplies it-self in several ways which wouldbe too tedious to detail here. Butwhen fresh bright green mats can beobtained they should be placed ina large vessel of water and set ina cool place. Only a small amountof the alga should be placed in avessel, since decaywill set in morerapidly with a largequantity. For several days oneshould look for small green bodies which may be floating at the side of the vesselnext the lighted window. 300. Zoogonidia of vaucheria.—If these minute floating green bodies arefound, a small drop of water containing them should be mounted for exami- 142. r ig. of branched thread o. ?auchena VAUCHERIA, H3 nation. If they are rounded, with slender hair-like appendages over thesurface, which vibrate and cause motion, they very likely are one of thekinds of reproductive bodies of vaucheria. The hair-like appendages arecilia, and they occur in pairs, several of them distributed over the rounded bodies are gonidia, and because they are motile they arecalled zoogonidia. By examining some of the threads in the vessel where they occurred wemay have perhaps an opportunity to see how they are produced. Shortbranches are formed on the threads, and the contents are separated fromthose of the main thread by a septum. The protoplasm and other contents ofthis branch separate from the wall, round up into a mass, and escape throughan opening which is formed in the end. Here they swim around in thewater for a time, then come to rest, and germinate by growing out into atube which forms another vaucheria plant
Size: 1544px × 1618px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthoratk, bookcentury1900, bookdecade1900, booksubjectbotany
