Issued on January 10, 1945 by French Indochina, this $1 piastre green and yellow stamp belongs to the “Personalities” series, commemorating the Swiss-French physician and bacteriologist Alexandre Yersin (1863–1943), who is remembered for his groundbreaking discovery of the plague bacillus and for his significant contributions to medicine and science in Southeast Asia. Designed by Bùi Trang Chước and printed at the Imprimerie d’Extrême-Orient in Hanoi, the stamp measures 26 x 41 mm and was produced by offset lithography without watermark and without gum. The portrait of Yersin is framed by a decorative border including symbolic motifs such as the caduceus, reflecting the theme of science, health, and human progress. Issued as a definitive daily-use stamp with a print run of 1,519,950 examples, it is catalogued as Yvert & Tellier FR-IC 291, Michel FR-IC 338, Scott FR-IC 236, and Stanley Gibbons FR-IC 295. With its vivid yellow-green color scheme, clear portrait, and strong thematic relevance to both philatelists of Indochinese history and collectors of scientific personalities, this issue remains one of the most culturally significant stamps of mid-20th century Indochina. Comparable examples have appeared at auction and continue to attract strong interest due to both its historical subject and its place within colonial philately. Condition: Used, postmarked, with intact perforations and legible design, natural wear from postal circulation. Stamps of this issue in circulated condition generally trade between $25 and $50, with higher values for well-centered and lightly cancelled examples.