On the origin of double monstrosity / by Bertram C.A. Windle.

  • Bertram Coghill Alan Windle
Date:
[1889]
Catalogue details

Licence: Public Domain Mark

Credit: On the origin of double monstrosity / by Bertram C.A. Windle. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    development. In other words, in cases of duplicity a fission of multiplication precedes the fission of formation. This conclu- sion would throw back the period of fission to an earlier date than has been fixed by most writers, even the most recent, as for example Bom,^ but I am inclined to believe that it is the most legitimate deduction from the facts detailed. If fission, then, occurs as the first incident in the develop- ment of the double form, it remains to inquire what cause, if any, can be assigned for its occurrence. Professor Cleland has, in several papers, recently stated his belief that irritation of some kind is this cause. Thus, he says,^ “ every vertebrate animal has, at an early period of its existence, a latent capacity of splitting up indefinitely;” and^ “ double monstrosity consists in the outbreak of proliferation at an unusual period, with consequences dependent on the greater or less perfection of the process, and this outbreak we may fairly impute to irritation.” Finally,^ “ over-stimulation, when it occurs soon after impregnation of the ovum, leads to fissi- parous division of the germinal mass, resulting in two embryos ; at a later period, or carried to a slighter extent, it will cause partial division.” In this opinion he agrees with other ob- servers, amongst whom may be mentioned Knoch,® who, from his experiments on ova developed in still and running water, the latter affording the greater number of double forms, believed that the agitation was the causative irritation. Ahlfeld® attributes the cleavage to “a faulty relation be- tween zona pellucida and embryo,” and his reasons will be found in his well-known work. Kidd’^ formulated the idea which others have held, and which has been criticised by Ahlfeld, that the cause is to be found in a superabundance of formative material. “ The formative germ,” he says, “ is likely to suffer ^ Ueh. die Furck. des Eies bei DoppelmissMld, Bresl. drtzl. zts., No. 15, 1887; V. u. H. Jahresh., i. 269, 1887. ^ Op. cLt., p. 11. * “Address to Section of Anatomy and Physiology,” Brit. Med. Jour., p. 346, August 18, 1888. * “Teratology, Speculative and Causal,” Mem. and Memo, in Anat., p. 128. ® Ahlfeld, ut infra. * Missbild. des MenscTien, vol. i. s. 9, Leipzig, 1880. ’’ Dub. Jour. Med. Sci., N.S., vol. xxxiii. p. 464.
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