Lazzaro Spallanzani (Italian pronunciation: [ˈladdzaro spallanˈtsaːni]; 12 January 1729 – 11 February 1799) was an Italian Catholic priest (for which he was nicknamed Abbé Spallanzani), biologist and physiologist who made important contributions to the experimental study of bodily functions, animal reproduction, and animal echolocation.

Persuaded by his father and with the help of Monsignor Castelvetro, the Bishop of Reggio, he studied law at the University of Bologna, which he gave up soon and turned to science.

[4] In 1763, he was moved to the University of Modena,[5] where he continued to teach with great assiduity and success, but devoted his whole leisure to natural science.

His return home was almost a triumphal progress: at Vienna he was cordially received by Joseph II and on reaching Pavia he was met with acclamations outside the city gates by the students of the university.

While he was travelling in the Balkans and to Constantinople, his integrity in the management of the museum was called in question (he was accused of the theft of specimens from the university's collection to add to his own cabinet of curiosities), with letters written across Europe to damage Spallanzani's reputation.

[7][8] In 1796, Spallanzani received an offer for professor at the National Museum of Natural History, France in Paris, but declined due to his age.

After his death, his bladder was removed for study by his colleagues, after which it was placed on public display in a museum in Pavia, where it remains to this day.

His indefatigable exertions as a traveller, his skill and good fortune as a collector, his brilliance as a teacher and expositor, and his keenness as a controversialist no doubt aid largely in accounting for Spallanzani's exceptional fame among his contemporaries; his letters account for his close relationships with many famed scholars and philosophers, like Georges-Louis Leclerc, Comte de Buffon, Lavoisier, and Voltaire.

[6] Spallanzani's first scientific work was in 1765 Saggio di osservazioni microscopiche concernenti il sistema della generazione de' signori di Needham, e Buffon (Essay on microscopic observations regarding the generation system of Messrs. Needham and Buffon) which was the first systematic rebuttal of the theory of the spontaneous generation.

He managed to capture three wild bats in Scandiano, and performed a similar experiment, on which he wrote (on 20 August 1793): Having seen this, the candle was taken away, and for my eyes like for those of my brother and cousins we were in complete darkness.

He repeated his experiments by using improved ear plugs using turpentine, wax, pomatum or tinder mixed with water, to find that blinded bats could not navigate without hearing.

[19][20] Spallanzani studied the formation and origin of marine fossils found in distant regions of the sea and over the ridge mountains in some regions of Europe, which resulted in the publication in 1755 of a small dissertation, "Dissertazione sopra i corpi marino-montani then presented at the meeting the Accademia degli Ipocondriaci di Reggio Emilia".

Although aligned to one of the trends of his time, which attributed the occurrence of marine fossils on mountains to the natural movement of the sea, not the universal flood, Spallanzani developed his own hypothesis, based on the dynamics of the forces that changed the state of the Earth after God's creation.

His concern with fossils witnesses how, in the style of the eighteenth century, Spallanzani integrated studies of the three kingdoms of nature.

[11] In 1777, he gave the name Tardigrada (from Latin meaning "slow-moving") to the phylum of minute extremophile animals also called water bears.

He embodied the results of his research in a large work (Viaggi alle due Sicilie ed in alcune parti dell'Appennino), published four years later.