This obstetrical wax model and item XVIII.57 describe embryotomy. Shown here is the application of the lever to the head of the fetus in order to extract it from the superior strait after decapitation in a breech birth. This type of lever was diffused in Europe nearly at the same time as forceps (c. 1765), but it did not become popular and was almost completely abandoned in the early decades of the twentieth century. It was most commonly used in cases where the head was blocked between the pelvic bones. This happened after a decapitation in a shoulder presentation, or when the obstetrician had applied excessive traction while attempting to extract the fetus manually.

The model was commissioned by Felice Fontana, who was working on the installation of the Museo di Fisica e Storia Naturale of Florence, from the sculptor Giuseppe Ferrini and his assistant Clemente Susini.