THE HUMAN "POSTAL SYSTEM."

Press, Volume LIX, Issue 17770, 23 May 1923, Page 9

THE HUMAN "POSTAL SYSTEM."

IN NATURE'S WORKSHOP.

HOW GIANTS AND DWARFS ARE

MADE. (FROM OTO OWST COKBRSPOSDENT.) LONDON, April 13. Londoners have had ample opportunity of gaining a superiicial knowledge of innumerable scentilic subjects by attending the lectures of the Royal Institution. It is hero, of course, that the great scientists of the past half century have made history with their revelations, and to-day just in tho same way are modern authorities revealing to the public tho results of their rese-arcn and study. In tho excellent ser.es of lectures that has now begun ouo may learn tho most up-to-date things about wireless telegraphy or about the ilowors of Greenland, the jewels of the ltenaissance or the nature of enzyme Action. This week Sir Arthur Keith Prolessor of Physiology; gave the tirst of lus lectures on tno of Human involution." NVe might be quite certain, he said, that tho principles which governed t*ie evolution of the animal and which existed in ages long past wcro here 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 growing child Nature was using the identical methods alio had used in effecting her miracles of evolution. Hencef at tho 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 part —springs as a bud from the brain ; another, which forms the-;lens, is produced fom the outlying skin. In experiments the eyebud had been transplanted 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 ueighV bouring part. Tweutv years ago it was found that the living units of the body bad an unsuspected method of communicating with each other by means of chemical messengers or 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 elauorate postal system was. also in active operation. Untold billions of living units which make up a human body "depend on the circulating blood to bring them food and refreshment, but also rely on it to serve as a vehicle to carry away their refuse. They also utilise the same stream for the conveyance of their postal traffic. Through their pos- , tal 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 hormone system wliicli Nature -uses, in shaping new forms of man and beast. A New Discovery. Although the ancient Egyptians had not formulated the theory or hormones, they knew the practical side of the doctrine. They knew that the removal of the seed giands altered the mental nature and outward 'appearance or domestic animals:. At an early period they found but that man was just litse 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 slim, the rugged olid, strong features of manhood \vere toned 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. surgical operation. More remarkable still is the manner, in which the mind is changed; aesires to rival and to fight give way to placidity and shyness. We thus see that tho "chemical messengers'.' sent out by the l 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 ihjtb frogs, and what is true of tadpoles in this respect also holds for children. If the thyroid fails to send out 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 .strange disorder known as acromegaly. Eight years ago Ihe 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 50oz normal), heart 290z (against lOoz normal), liver 188 os (against 520z normal).. This was all due to a tumour on the brain whichi had brought about an overgrowtn of the pituitary gland. 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. ; iThis is the most important of all the pinions of Nature's growtb-regulatincr machinery. Its overgrowth, as in the above ease, may give tho body and feajnires the huge and grotesque appearances seen in acromegaly. Its repression, through a tumour outside it, may bring , r about a peculiar form of dwarfism; : These abnormalities give an indication of the normal functions of the parts of the human body of which so little is known.