6S2 THE PHYSIOLOGY OF REPRODUCTION 



of occurrence of abortion among horses, but the experience of 

 breeders shows, that the losses arising from this cause are very 

 considerable, and that they are greatest amongst the better-bred 

 animals. One of the earlier reports of the Eoyal Commission on 

 Horse-Breeding stated that in this country in any given year no less 

 than forty per cent, of the mares chosen for breeding fail to produce 

 foals, but to what extent this result is due to sterility or how far it 

 may be ascribed to abortion does not appear to have been ascertained. 



The causes of abortion are diverse, and may be mechanical, 

 psychological, physiological, or pathological. Deliberate abortion 

 among civilised European nations is a criminal offence punishable 

 by law, but nevertheless is not infrequently carried out. In 

 Oriental countries and among savages abortion is practised more 

 openly. The more usual means are drugs (ergot, ethereal oil of 

 juniper, yew, turpentine, camphor, cantharides, aloes, etc.),^ but none 

 of these is infallible, and owing to their toxic properties their use 

 is . often accompanied by danger. Haddon ^ says that among the 

 Eastern Islanders of the Torres Straits abortion is procured by 

 the leaves of the shore convolvulus and certain other plants. Also 

 the old women give the younger women young leaves of the 

 argerarger {Callieaiya sp.), a large tree with inedible fruit, and bok, 

 a large shrub. When a woman's body is saturated with the juice 

 from the leaves, she is believed to be proof against fecundity, and 

 can indulge in sexual intercourse without fear of becoming pregnant. 

 Probably the toxic substances introduced cause abortion at very 

 early stages of pregnancy, or even inhibit pregnancy at the very 

 outset. Abortion is sometimes procured by purely mechanical 

 means — e.g. blows, massage, hot injections,^ carrying heavy loads,* 

 etc. But although mechanical and psychological influences, both 

 voluntary and involuntary, play a part in bringing about abortion, 

 the'y are probably less frequently concerned in the process than 

 pathological conditions existing either in the embryo or in the 

 maternal organism. 



Among the causes of abortion in women Kelly ^ mentions 

 haemorrhage of the chorion, imperfect vascularisation of the amnion, 

 hydatiform degeneration of the chorion, circulatory disturbances 

 caused by heart lesions in the mother, various infections of the 

 mother (notably syphilis), psychic disturbances, and excessive 

 cohabitation, acute poisoning (by alcohol, phosphorus, lead, etc.), 



1 Bloch, loc. eit. 

 ^ Haddon, loc. cit. 

 ^ Bloch, loc. cit. 

 * Haddon, loc. cit. 



^ Kelly, loc. cit. See also Oliver, "The Determinants of Abortion," Brit. 

 Med. .Jour., .30th November 1907. 



