MONTESSORI, Maria (1870-1952). Autograph letter signed ("Mammolina"), to Adele Costa Gnocchi. London, n.d. [c.1946]. 1 page, 4to, on Twenty-Eighth International Training Course in Education letterhead, creased at folds, paperclip stain on upper margin, with original holograph envelope. Writing a teasing letter to her former student and advocate, on her silence: "So Adelina, what happened? Such an impressive silence! I am sure you are alive and healthy. Some problems are perhaps closing up your heart? Speak! Open up to your confidante." Adele Costa Gnocchi was a philosophy professor and a student of the educator Maria Montessori. In 1947, she developed the Assistants to Infancy course, for children from birth to three years of age, in close consultation with Montessori.