28 



Mr. F. H. A. Marshall. On the Effects of [Dec. 20,. 



to men. Abnormalities in the ovaries have been described as producing 

 similar results. Thus, Eorig* records three cases in which female deer 

 possessed horns, and were shown on dissection to have had abnormal ovaries. 

 Darwin* states that female deer in old age have been known to acquire 

 horns. E. Wallace* says that in old mares the neck tends to acquire an 

 arch as in the stallion. The occasional growth of hair on the face in old 

 women is a phenomenon of the same kind. Similar observations have been 

 made upon birds, especially ducks, poultry, and game birds. Darwin 

 mentions the case of a duck which, when 10 years old, acquired the plumage 

 of the drake. Other cases are those of hens which in old age assumed 

 secondary male characters and started to crow. Hunter* mentions a hen 

 pheasant which had male plumage associated with an abnormal ovary. 

 Numerous other instances have been described, but it is not apparent that 

 such an acquirement of male characters by female individuals is always 

 correlated with an abnormality in the reproductive organs. According to 

 Gurneyf the assumption of male plumage is generally associated with 

 sterility in female gallinaceous birds, but not, as a rule, in female passerine 

 birds. Thus Gurney describes a hen chaffinch with male plumage and an 

 unlaid egg, and a hen redstart with male plumage and a number of 

 developing eggs. 



Guthrie} has described an experiment in which the ovary was removed 

 from a fowl. After the removal an ovary from another fowl was engrafted,, 

 but the transplanted ovary underwent degeneration. " The pullet acquired 

 not only the outward anatomical features of a cock — cock's comb, wattle, 

 long hackle and tail feathers, rapidly developing spurs, carriage, etc., but the 

 behaviour as well was that of a male ; it exhibited the pugnacious attitude 

 towards other cocks, was attracted by hens, and even went so far as to tread 

 hens as a cock." 



Goodale§ records two experiments in which the ovaries were removed 

 from ducks. One was operated upon in the early spring of 1909 and the- 

 other in August, and both were still alive at the time of writing (November, 

 1910). The first bird had only undergone a slight change in plumage, but 

 the second made a definite though gradual advance towards the male type.. 

 This bird is described as having come closely to resemble the drake in 

 summer plumage, possessing brilliant green feathers on the head, a white 



* For references see Marshall, ' The Physiology of Beproduction,' London, 1910. 

 t Gurney, " On the Occasional Assumption of Male Plumage by Female Birds," ' Ibis, r 

 1888, vol. 6 (5th series). 



% Guthrie, "Survival of Engrafted Tissues," ' Journ. Exper. Med.,' 1910, vol. 12. 

 § Goodale, "Some Eesults of Castration in Ducks," 'Biol. Bull.,' 1910, vol. 20. 



