The fact that an oxidizing system of the type used to delignify annual plant tissues was required to obtain the polysaccharides suggests that the Chlorella wall consisted of polysaccharides crosslinked with a phenolic units similar to those in lignin The fact that hot alkaline solutions did not extract polysaccharides (data not given ) suggests that crosslinkages involving ester bonds were not present. That leaves the possibility that the cell-wall polysaccharides may be crosslinked with phenolics in ether linkages.