Elementary botany . Fig. sessilis, one antheridium between two oogonia. the antheridium forms numerous small oval bodies each with twoslender lashes, the cilia. When these are formed the antherid-ium opens at the end and they escape. It is after the escapeof these spermatozoids that the antheridium is collapsed. Eachspermatozoid is a male gamete. 304. Oogonium.—The oogonia are short branches also, butthey become large and , % somewhat oval. The / * septum which separates theprotoplasm from that ofthe main thread is as wesee near the junction ofthe branch with the mainthread. The
Elementary botany . Fig. sessilis, one antheridium between two oogonia. the antheridium forms numerous small oval bodies each with twoslender lashes, the cilia. When these are formed the antherid-ium opens at the end and they escape. It is after the escapeof these spermatozoids that the antheridium is collapsed. Eachspermatozoid is a male gamete. 304. Oogonium.—The oogonia are short branches also, butthey become large and , % somewhat oval. The / * septum which separates theprotoplasm from that ofthe main thread is as wesee near the junction ofthe branch with the mainthread. The oogonium,as shown in the figure, isusually turned somewhatto one side. When mature the pointed end opens and a bit of theprotoplasm escapes. The remaining protoplasm forms the largerounded egg cell which fills the wall of the oogonium. In someof the oogonia which we examine this egg is surrounded by athick brown wall, with starchy and oily contents. This is the. Fig. sessilis ; oogonium opening and emit-ting a bit of protoplasm; spermatozoids; sperma-tozoids entering oogonium. (After Pringsheim andGoebel.) VA UCHERIA. 145 fertilized egg (sometimes called here the oospore). It is freedfrom the oogonium by the disintegration of the latter, sinks into
Size: 2335px × 1070px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthoratk, bookcentury1900, bookdecade1900, booksubjectbotany
