It was only under the direction of Alexandre Boreau (1803–1875) that the museum was enlarged, with new halls on the first floor of the Barrault House being inaugurated in 1849. The same year the museum was enriched with the collection of Pierre-Aimé Millet de la Turtaudière (1783–1873). His collection consisted mainly of fossils from the tuffeau limestone and "faluns" of Anjou, but today it has almost entirely disappeared. In 1864, a temporary exhibition of geology became a permanent exhibit. In 1871, the Society of Scientific Studies of Anjou (SESA) is established by a group of scholars strongly linked to the museum. In 1883 Alphonse Milne-Edwards (1835–1900), Professor of Ornithology at the National Museum, donated 65 birds to the Muséum d'Angers.