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Spallanzani, Lazzaro

bats insects experimental generation

[spalant sah nee] (1729–99) Italian biologist: pioneer of experimental physiology.

Spallanzani first studied law, but his cousin , who was professor of physics at Bologna, encouraged his interest in science. He became a priest and eventually professor of natural history at Pavia, and was an enthusiastic traveller in pursuit of specimens for the natural history museum there. His other enthusiasm was experimental physiology and especially reproduction. The older biologists had largely believed (with ) in spontaneous generation (eg from mud or an animal corpse). A fellow Italian, F Redi (1626–97), had shown in the 17th-c that insects developed on meat only from deposited eggs; Spallanzani showed in 1765 that well-boiled broth, hermetically sealed, remained sterile. (Despite this, it was not until work, a century later, that the idea of spontaneous generation was largely abandoned.) He also studied digestion, which had thought to be a kind of cooking by stomach heat, while had experimented with buzzards and concluded it was solvent action. Spallanzani experimented with many animals and one man (himself) and showed that gastric juice is the active digestive agent. He was the first to observe blood passing from arteries to veins in a warm-blooded animal (the chick). He achieved artificial insemination of amphibians, silkworms and a spaniel bitch, although he did not grasp the importance of spermatozoa (which had been discovered much earlier) and believed that the ovum contained all the parts that appeared later in the embryo. He worked on the senses of bats, and found that blinded bats could still catch insects and navigate well enough to avoid even thin silk threads. (L Jurine showed they lost their skill if their ears were covered, which was not explained until 1941 – bats use sonar.) His interest in zoology was mainly in marine biology, including sponges and Torpedo , and in rotifers and tardigrads.

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