NATURE'S WORKSHOP

Evening Post, Volume CV, Issue 124, 26 May 1923, Page 8

NATURE'S WORKSHOP

THE HUMAN "POSTAL SYSTEM" CHEMICAL MESSENGERS IN THE BODY HOW GIANTS AND DWARFS ABE MADE. (FROM OUR OWN CORRESPONDENT.) LONDON, 13th April. Londoners have ample opportunity of gaining a superficial knowledge of innumerable scientific subjects by attending the.lectures of the Royal Institution. It is here, of course, that the great scientists of the past half century have made history with their revelations, and to-day just in the same way are modern authorities revealing to the public the results of their research and. study. In the excellent series of lectures that has now begun one may learn the most up-to-date things about wireless telegraphy or about the flowers of Green- j land, the jewels of the Renaissance, or the nature of Enzyme Action. This week Sir Arthur Keith (Fullerian Professor of Physiology) cave the first of his lectures on the ''Machinery of Human Evolution." . -

We might be quite certain, he said, that the principles which governed the evolution of the animal kingdom, . and which existed in ages long past were here and with us now. There was one safeguarding principle in research work, that the machinery, whatever it was was still silently working in our bodies, and in the growin* child Natune was using the identical methods she, had used in effecting her miracles of evolution. Hence, at the present time all their energies were directed to find out how the growth of the human body was regulated.

During the formation of the embryo one part of the eye—the recording partsprings as a bud from the brain; another, which forms the lens, is produced from the overlying skin. In experiments the eye bud had been transplaisfed to another part of the embryonic brain, and had caused, the new area of skin, overlying it to form a lens, thus showing that one part of the embryo could control the growth of a neighbouring part.

Twenty years ago it was found that the living units of the body had an unsuspected method of communicating with each other by means of chemical mes- | sengersor hormones. We know that the. nerve system of our bodies serves as a telegraphic means of communication between its various parts, but we never supposed that an elaborate postal system was ateo in. active operation. Untold billions of living unite which make | up a human body depend on the circulating blood to bring them food and refreshment, but also rely on it to serve asa vehicle to cany away their refuse. They also utilise ■, the same stream for 1 the conveyance of their postal traffic. Through their postal system in the blood stream each unit of the body can make ; its individual wants known and can be duly informed of the needs of that part of the community with which it has to do. It is this immense and complex postal or horj mono system which nature uses in shaping hew forms of man and beast. ■A NEW DISCOVERY. Although the ancient Egyptians had not formulated the theory of hormones, they knew the practical side of the doctrine. They knew that the removal of the seed glands altered the mental na-* ture and. outward appearance of domestic animals. At an early period they: found out that man Was just like other animals, and if an operation was done in childhood then all the changes which transform a lad at puberty were ■ suppressed; the voice did not break, the beard did not grow, the limbs became long and elim, the rugged and strong features of manhood were tonod down. It had recently been found that there lay over each kidney a small body fashioned out of the same substance as that which formed the seed glands.' Sometimes this took on a malignant 'growth in childhood, with the result that the child, whether male or female, developed premature manifestations of manhood or womanhood. This could be cured by a 6lirgical operation. More remarkable still is the manner in which the. mind is changed; desires to rival and to fight cive way to placidity and shyness. 'We thus see that the "chemical messengers" sent out by the seed glands form an important part of the machinery employed by nature in moulding the evolving forms of mankind. Undoubtedly the thyroid gland in the neck has an active share in moulding the form of man's features. In quite recent years experimenters have made clear how potent 'the extract of this gland is during the transformation of the tadpoles iuto frogs, and what is trus of tadpoles in , this respect also holds, for children. If the thyroid fails to send put its due supply of messengers, then there result these hideous human dwarf children known as cretins. THE HAMMERSMITH GIANT. The lecturer referred to an inquest that had been held at Hammersmith recently. It was the case of a man who had died of a stratusa disorder known as acromegalv. Eight years ago. the man was normal, and had joined the Army. The description given of him at the inquest was "enormous hands and feet, a great head, weight 23 stone, chest measurement 53 inches, very tall, brain 640z (against SOoz normal), heart 290z (against lOoz normal), liver 138oz {against, 520z normal). This was all due to a tumour on the brain., which had brought about an overgrowth of the pituitary eland. This in healthy people is of the size of a small bean, and lies on the floor of the skull attached to the oldest part of the brain. This is the most impprtant of all the pinions of Nature's growth-regulating machinery. Its overgrowth, as in the above case, may give the body and features the huge and grotesque appearances seen in acromegaly. _ Its repression, through a tumour outside it, may bring about a peculiar form of dwarfism. These abnormalities cive an. indication of the normal functions' of the parts of the human body of which so little is known.