coat structure in white bean seeds

[leosilv]

Hi,
while observing detached white bean testa in optical microscopy, I saw some long helical structures - seemingly included in thiny walled pipes (not sure of this) and roughly 20 µ large - laying onto the coat plane and assembled in branched bundles (jpeg attached). They stain blue in 0.2% toluidine bue. Some information on such strutures will be greatly acknowledged. Thanks You all

012BF.jpg (16.29 KiB) Viewed 1848 times

[JackBean]

That seems like xylem to me. But you saw it on(?) the seeds?

[leosilv]

Unexpectedly , I saw such branched bundles planarly embedded in the thin leaflet just below the external seed surface. Why there? May be they have a role during imbibition. Thanks