160 – He is here referring to Virg. Ecl. 5, 77. Dumque thymo
pascuntur apes, dum rore cicadae.
161 – Here again he is thinking of Virg. Georg. 3, 328. Et cantu
querulae rumpent arbusta cicadae.
162 – Here again S. Ambrose is thinking of Virg. Georg. 2, 154.
Squameus in spiram tractu se colligit anguis.