HEREDITY

Evening Post, Volume CV, Issue 106, 7 May 1928, Page 4

HEREDITY

■» APPLICATION TO MAN AN IMPORTANT PROBLEM There was a good attendance at the Red Cross Hall on Saturday night, when Professor H. B. Kirk, of Victoria University College, delivered his last address in the short course on genetics, under the auspices of the Workers' Educational Association. The subject of the lecture was the "Application of the Principles of Heredity." The speaker explained the phenomenon known as cytoplasmic inheritance—the inheritance of qualities that have their seat, not in the chromosomes of the nucleus, but in the ordinary protoplasm of the cell, outside the nucleus. The green colour of plants, said Professor Kirk, was due to the presence of the pigment chlorophyll, which was produced in specialised parts called plastids, and if a plant cell cut off from its sister cell contained no plastids it could form none, and could never take on the green colour. The pollen grains of a plant did not, in most cases at all events, have any plastids; and thus the male sex cells, which owe their origin to' the pollen grains, have none, but consisted almost entirely of nuclear matter. The lecturer gave several examples of hybridised plants with special features, and explained that in plant and animal breeding many hybrids possessed much greater vigour than their purebred parents. He showed that the breeder of plants had frequently a great advantage over the breeder of animals in the conservation of the vigour resulting from crossing, for, having obtained a hybrid generation by crossing two desirable races, he could, in many cases, propagate the hybrid vegetatively, and so keep his plants at the high level of vigour to which the crossing brought them for many years. Such a plan would be eminently suitable in the case of New Zealand flax, said the lecturer, but it could not, of course, be applied in the case of an annual such as wheat. Other desirable qualities such as fertility, immunity from disease, content of gluten, etc., could also be obtained by crossing. THE HUMAN PROBLEM. "There is one animal in regard to whose breeding man takes, generally speaking, no care whatever," said Professor Kirk, and that animal is himself. It is probable, moreover, that man will never decide that only the best members of the race should propagate, but it is quite certain that he is being driven towards the adoption of measures that shall prevent the worst and most undesirable members of the race from propagating unchecked. The existing state of society lays on every civilised community an ever-increasing burden of unfitness, in addition to the cost and sorrow that it brings, and it is beiu? recognised that many forms of crime are the outcome of hereditary taint. Yet except when a long term of imprisonment brings about incidentally an advantage that was not aimed at, we do nothing to prevent the passing on of the tendency. It is an undisputed fact that insanity and mental deficiency are inherited, and that where one occurs in a family the other is frequently present." The lecturer quoted figures to show how alarmingly prolific is the breeding of mental deficients, due largely to their want of control and natural fertility, and he expressed the opinion that it was a happy thing for the human race that so many of the qualities which make for good citizenship were also inheritable. A number of interesting lantern slides were shown. At the close of the evening a very hearty vote of thanks was accorded to the lecturer for' his fine series of lectures.