(Source: Index card file. "Governors" --- attributed to Jean Lorrah) "Secondary maturation characteristic" of Gens. Complex linkage of hormones, etc. that regulate selyn production, turning it off at maximum saturation, and on again when bleedoff losses bring selyn content below maximum. If they don't work and no selyn is produced, GEN can die of attrition!!
(Source: Index card file. Sime Surgeon -- http://www.simegen.com/sgfandom/rimonslibrary/surgeon/SURGEON1.html) A highly complex linkage of glandular hormones and enzymes which stop selyn production in Gens when the body is charged to its maximum tolerance. When these fail, underdraw occurs.