Provisional maps are given for the two smallest autosomes (chromosomes 21 and 22) at pachytene in the human male. The longer of the two consists of 10 chromomeres in a standard sequence of various sizes, and the shorter one of 6 such chromomeres, including in each case the large terminal chromomere within which the centromere is located. With increasing compaction many of the details of these chromomere patterns disappear. Nevertheless, the two bivalents remain distinguishable from each other by their having, in addition to the large terminal chromomere, three and two major markers, respectively. Maps are given both at the extended and compacted stages.