Word: pupa
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Dates: during 1950-1959
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...winner of the 1939 Nobel Prize in Chemistry (for isolating the male sex hormone, androsterone), a research team at Munich's Max Planck Institute for Biochemistry imported 1,000,000 silkworm cocoons from Italy and Japan, opened them up with razor blades, separated the pupae of 310,000 females from the males. What followed, in the words of one researcher, was "a mass slaughter, and not for the fainthearted." Each tiny pupa was disemboweled, the scent glands carefully cut out. Male moths served as lab assistants: when they were placed near fractions into which the gland material had been...
Biologists guessed a generation ago that the metamorphosis of insects (changing from larvae to pupae and from pupae to adults) is probably controlled by a chemical hormone. Three years ago Dr. Williams extracted an oil from the abdomens of silkworm moths, injected it into silkworm pupae. It stopped their normal development. The pupae never became adult moths, instead developed into a second kind of pupa. Smaller doses brought forth monstrosities with mingled patches of adult and juvenile tissue. Williams concluded that the oil contained a "juvenile hormone...
...this experience, both males and females are sterile but otherwise undamaged. When they emerge from the pupa cases two days later as vigorous adults, they are packed into small cartons, loaded into airplanes for release over Florida and parts of adjacent states...
...other hand, when sex cells were placed in the blood of the dormant pupa--where the hormone is absent, and where the animal is not growth--the sex cells underwent no change...
Sleeping Pupa.The three "cytochrome" enzymes are basic growth factors. Present in human beings as well as in silkworms, they control the utilization of oxygen in the tissues. Without them growth is impossible. The dormant Cecropia pupa contains no cytochrome enzymes. Therefore it cannot grow until they are provided by the chain of hormones that starts in its brain...