Science: Nottingham Lace

Some molecules are so small that they contain only one atom. Some are so large that they contain hundreds, thousands, possibly millions of atoms. Although they cannot be seen under the microscope, the giant, complex molecules of proteins are among the most important targets of current research in biological chemistry. Until recent years not much was known about them except that they were very big; that they contained carbon, hydrogen. oxygen, nitrogen and sometimes sulphur and phosphorus; that in such animal processes as digestion they were broken down by protein-wreckers called enzymes and that they were composed of polypeptide chains which might, presumably, be contorted in any number of patterns.

Then Svedberg, Wyckoff and others weighed & measured the giants by whirling them in powerful ultracentrifuges. Stanley found that the virus which causes tobacco mosaic disease in plants is a huge molecule, which was weighed by Svedberg and Wyckoff at 17,000,000 times as much as a hydrogen atom. The virus of noninfectious rabbit warts was isolated as a protein molecule weighing 20,000,000 units.

The tough question of the atomic architecture inside the molecule has yielded somewhat to the discovery that it must conform to mathematical limitations grouped under “stoichiometrical law.” Stanley’s tobacco mosaic virus, for example, was found to be not a long, thin chain but roughly egg-shaped.

To the British Association for the Advancement of Science which got under way last fortnight at Nottingham (TIME, Sept. 13), and concluded its sessions last week, tidy, calm-browed Dr. Dorothy M. Wrinch of Oxford described her latest discoveries about the architecture of molecules. She showed a model of protein molecules which she had built after working them out mathematically. One typical globular molecule looked like a crocheted doily cut up and sewed together in a three-dimensional geometrical object. This she described as a “polyhexagonal lacelike pattern of atoms with the characteristic lacunae or holes, the whole forming a truncated tetrahedron, a cage-like space enclosing a structure roughly resembling a six-point diamond.” Molecules in this weight class were called “space-enclosing cyclols.” Significance of this work is that the way a molecule is built is bound up with its chemical behavior.

Other noteworthy discussions of the B. A. A. S. sessions:

Fish Minds. Professor James Gray of Cambridge declared that fish: 1) perform simple reflex acts; 2) form associations between events; 3) accomplish difficult migrations apparently involving memory; 4) display emotion. “As far as I can form a judgment,” said he, “these four types of behavior include most, if not all, of the activities of the human race. … I do not believe we can put our finger on any one of our mental powers and say, ‘Herein are we a race apart, elevated above the rest of the animal world.’ ”

As an example of association in fish Professor Gray pointed out that monks in certain monasteries used to call up fish at feeding time by ringing a bell, that this has been duplicated in the laboratory: a bell is rung at fixed intervals before the food is presented; after a number of repetitions, the fish begin moving toward the customary feeding point as soon as the bell starts ringing.

Sex & Age. “The true recipe for longevity,” said Dr. F. A. E. Crew of University of Edinburgh, president of the zoology section, “is to be born a girl.” Dr. Crew found informative reading matter in the British Statistical Review of the Registrar-General. In the tables for 1935 he found that in England and Wales 105.6 boys were born for every 100 girls. Of babies who died in the last three months of pregnancy there were 110 boys to 100 girls. And after birth the mortality rate at all ages was higher for males than for females. Thus although boys constituted a majority of infants, in adolescence the proportion of sexes grew even, and thereafter the proportion of women continuously increased until in the group over 85 years there were more than twice as many crones as gaffers.

One of the great discoveries of modern genetics is that certain hereditary characters are linked to the sex factor. Males manufacture two kinds of spermatozoa, one bearing a y-chromosome, the other an x-chromosome. If a y-chromosome spermatozoon happens to penetrate the female ovum, the get is a boy; if an x-chromosome, it is a girl. Thus Professor Crew reasoned the shorter life expectancy of the male seems to be carried on a gene or genes in the y-chromosome. By delicate manipulations, geneticists have had some success in separating male and female elements in mammalian sperm, opening the prospect of sex control in human reproduction—provided the parents will submit to artificial insemination by sperm from which one element or the other has been removed.*

Piety. The first murder in Biblical history was whitewashed in this wise by Professor Samuel Henry Hooke of the University of London: “I want to point out that Cain’s slaying of Abel was not jealous murder but a ritual for increasing the fertility of the soil. Recent finds in North Syria dating from, about the second millennium B. C. show that it was a ritual to kill a shepherd at the time of the summer drouth and that Cain probably worshiped by killing Abel.”

*Owl-eyed Biologist Julian Sorell Huxley predicted at Nottingham that the old dream of eugenists—human breeding by selected males and females only—would actually be put into practice within one or two generations. Said Dr. Huxley: “When people get used to the idea they will accept it just as they have accepted birth control.”