A New Cytoplasmic Component of Plant Cells

Dur ing an investigation of the relat ionship between the parasit ic flowering p lan t dodder (Cuscuta campestris Yuncker) and its hosts, an unusual cytoplasmic componen t was observed in cer tain of the dodder cells. Both in electron and in l ight micrographs our a t ten t ion was d rawn to the cytoplasmically rich cells at the tip of the newly initiated haustor ium, or sucker. These long cells appeared to conta in a previously undescr ibed cytoplasmic componen t in addi t ion to the structures commonly observed in p lant cells. Because of the unusua l na ture of this componen t and its prominence in the cells most actively involved in pene t ra t ion of the host, we have described its appearance and considered its possible role in the physiology of the host-parasite relationship.