WHAT IS TELEGONY?

Evening Star, Issue 19615, 22 July 1927, Page 1

WHAT IS TELEGONY?

DOES IT OCCUR IN MANf (By Professor J. Arthur Thomson, i* ‘John o’ London’s Weekly.’) Telegony is a term coined by Weismann to describe the influence of a previous sire t on offspring , (subsequently borne) by the same mother to a different sire. Thus many dog breeders are convinced that if a pure-bred bitch has had pups to a mongrel, her value is thereby greatly depreciated, the belief being that she will not afterwards breed true when paired with dogs of good breed. In other words, the influence of the mongrel (the previous sire) is supposed to Fast, so that subsequent offspring by a pure-bred' sire are specifically affected. SCIENTIFIC DOUBT. The statements made are sometimes very precise, though they are, almost never corroborated' by photographs. Thus we read that “if a pointer bitch gets accidentally served by a collie dog and produces a litter, the pups will be of various types, some like the pointer, some like tho collie, and some a blend. And let that pointer bitch be afterwards served by a pure pointer dog. the result will be a litter among which the collie type can be unmistakeably observed.” , , It may seem strange that we should write as if there were any doubt as to to the occurrence of telegony, especially since a belief in its reality is translated into £ s d among breeders, it is said to occur in horses, dogs, cats, sheep, cattle, pigs, rabbits, rats, mice, and pigeons. There is no doubt as to tho occasional occurrence of peculiar phenomena; the question is whether they can be interpreted as evidence of telegony. Thus there is an occasional occurrence of hark-backs or revisions, and there is often a rehabilitation of Mendelian recessives which have remained latent for generations.'- * MISINTERPRETED FACTS?

But when such things happen and are not understood it is natural that the breeder should lay the blame on some chance crossing. Especially natural will this bo when the chance crossing was followed by a family. But this is very apt to involve the “ post hoc, propter hoc ” fallacy. The breeder makes a scapegoat of the chance sire, whose influence is supposed to “infect the germ ” fertilised by a subsequent and reputable father. The only way to certainty is by experiment. The famous case of Lord Morton’s mare (1821), which Darwin discussed, concerned a nearly pure-bred Arabian chestnut mare which bore a hybrid to a q'uagga, and afterwards produced two colts hy a black Arabian horse. These colts were partially dnn-colored, and showed stripes on legs and some other parts. The mane was like a quagga’s, being short, stiff, and upright. This seems, at first sight very satisfactory, but the drawing of the most quagga■like colt is said to show only indistinct stripes, such as sometimes occur as reversions on pure-bred foals. A stiff mane may also occur as a variation among horses. , It is possible' that the quagga-crossbg had nothing to do with the peculiarities of the subsequent pi're-bred foals. f’ . , So it was with other experiments, the evidence was quite incbnclusive.

Negative cases do not, of course* prove that telegony never occurs; hundreds of experiments might be necessary before clear-cut, positive evidence was forthcoming. DOES TELEGONY OCCUR IN MAN?, There are plenty of surmises, but there is no certainty. We hear of e. white woman who lived for a while with a negro and afterwards, with a white man. The children by the second father had some negroid peculiarities! But man’s standard of accuracy —not to speak of veracity—is not high in regard to those matters. Professor Karl Pearson has approached the problem from the statistical side. If a female can bo influenced in a telegenic way by a previous mate, should there not be - in permanent. unions of a pair an increasing influence from the father’s side? lint there seems to be as regards stature, no such evidence of any increase in the father on a scries of children. it* is much to bo desired that those who live near the overlapping of distinct races should look out for suggestions of telegony in cases where the same mother has offspring first to a husband of one race and afterwards to a husband of another race. Faithfulness to the second husband would obviously have to he presupposed, if the case was to have any scientific value. An easier set of observations might bo made at home by comparing the families of the same mother by two successive husbands. Does the first husband continue to count?