Carroll Milton Williams (December 2, 1916 in Oregon Hill, Richmond, Virginia - October 11, 1991 in Watertown, Massachusetts) was an American zoologist known for his work in entomology

Entomology

Entomology is the scientific study of insects, a branch of arthropodology...

 and developmental biology

Developmental biology

Developmental biology is the study of the process by which organisms grow and develop. Modern developmental biology studies the genetic control of cell growth, differentiation and "morphogenesis", which is the process that gives rise to tissues, organs and anatomy.- Related fields of study...

 -- in particular, metamorphosis

Metamorphosis

Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation...

 in insects. He performed groundbreaking surgical experiments on larva

Larva

A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...

e and pupa

Pupa

A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...

e, and developed multiple new techniques, including the use of carbon dioxide

Carbon dioxide

Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

 as an anesthetic. His impact on entomology has been compared to that of Vincent Wigglesworth

Vincent Wigglesworth

Sir Vincent Brian Wigglesworth FRS was a British entomologist who made significant contributions to the field of insect physiology.In particular, he studied metamorphosis...

.

Williams was the first to isolate juvenile hormone

Juvenile hormone

Juvenile hormones are a group of acyclic sesquiterpenoids that regulate many aspects of insect physiology. JHs regulate development, reproduction, diapause, and polyphenisms....

 and ecdysone

Ecdysone

Ecdysone is a steroidal prohormone of the major insect molting hormone 20-hydroxyecdysone, which is secreted from the prothoracic glands. Insect molting hormones are generally called ecdysteroids. Ecdysteroids act as moulting hormones of arthropods but also occur in other related phyla where they...

, and discovered cocoonase

Cocoonase

Cocoonase is a trypsin-like proteolytic enzyme produced by silkworms as they near the final stages of their metamorphosis. It is produced by cells in the proboscis and exuded onto the galeae...

 and cytochrome b5

Cytochrome b5

Cytochromes b5 are ubiquitous electron transport hemoproteins found in animals, plants, fungi and purple phototrophic bacteria. The microsomal and mitochondrial variants are membrane-bound, while bacterial and those from erythrocytes and other animal tissues are water-soluble...

, as well as the "paper factor". He subsequently proposed that hormonal analogues could be used as pesticide

Pesticide

Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...

s by disrupting the developmental cycles of insects.

Williams was the chairman of the biology department at Harvard University

Harvard University

Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...

 from 1959 to 1962, and the Benjamin Bussey

Benjamin Bussey

Benjamin Bussey was a prosperous merchant, farmer, horticulturalist and patriot in Boston, Massachusetts, USA, who made significant contributions to the creation of the Arnold Arboretum....

 Professor of Biology from 1966 until his retirement in 1987., He was a fellow of the American Academy of Arts and Sciences

American Academy of Arts and Sciences

The American Academy of Arts and Sciences is an independent policy research center that conducts multidisciplinary studies of complex and emerging problems. The Academy’s elected members are leaders in the academic disciplines, the arts, business, and public affairs.James Bowdoin, John Adams, and...

, and was elected to the National Academy of Sciences

National Academy of Sciences

National Academy of Sciences commonly refers to the academy in the United States of America.National Academy of Sciences may also refer to :* National Academy of Sciences of Argentina* Armenian National Academy of Sciences...

, where he was a member of the Academy's council for two terms and chairman of biological sciences for one. He was also a member of the Institute of Medicine

Institute of Medicine

The Institute of Medicine is a not-for-profit, non-governmental American organization founded in 1970, under the congressional charter of the National Academy of Sciences...

, the Pontifical Academy of Sciences

Pontifical Academy of Sciences

The Pontifical Academy of Sciences is a scientific academy of the Vatican, founded in 1936 by Pope Pius XI. It is placed under the protection of the reigning Supreme Pontiff. Its aim is to promote the progress of the mathematical, physical and natural sciences and the study of related...

, and the American Philosophical Society

American Philosophical Society

The American Philosophical Society, founded in 1743, and located in Philadelphia, Pa., is an eminent scholarly organization of international reputation, that promotes useful knowledge in the sciences and humanities through excellence in scholarly research, professional meetings, publications,...

.