PHYSIOLOGY, CHEMISTRY AND PATHOLOGY 467 



females with diseased internal genitals (Rorig). Laignel-Lavastine and 

 Courbon, Hermans, and many others, have described cases of alteration 

 in the sex characters of man following orchitis, trauma and atrophy of 

 the testes. The degree of alteration in such cases is greatest in the young. 



Castration of brown Leghorn females, according to Goodale (c) results 

 first in the development of male characters, followed by the assumption 

 of the female type of plumage, and still later to the male type. Histo- 

 logical examination of the internal genitalia of castrated subjects showed 

 that remnants of the ovaries left from the operation had not degenerated, 

 and that a new organ had developed. This organ was neither testis nor 

 ovary in character ; however, its presence was necessary for the assumption 

 of male plumage. Removal of the testes of birds does not bring about the 

 assumption of female characteristics, but, at most, results in the loss of 

 certain male characters. Hence, as far as birds are concerned, it appears 

 that the female owes her color to the presence of some modifying element 

 which prevents the development of the male color. That is, it prevents the 

 appearance in the female of the male character which is inherited 

 equally by both sexes. The observations of Boring and Morgan are of 

 special interest in this connection. They point out that in the hen there 

 are groups of cells in the ovary (luteal cells) which produce yellow pig- 

 ment reacting similarly to the luteal pigment of the corpus luteum of the 

 mammal. These cells are absent in the adult male fowl except in case of 

 the Seabright cock, which is feathered like the female (hen-feathered). 

 Castration of these cocks results in the assumption of plumage common 

 to the ordinary male fowl. Hence these special cells through their secre- 

 tion suppresses in the hen and the Seabright male the characteristic cock 

 feathering. 



2. Sex-intergrades. Sex, according to the older conception, is an ab- 

 solute attribute; that is, an organism was supposed to be either male or 

 female except in cases of hermaphroditism. However, recent studies have 

 shown that the blending of "maleness" and "femalehess" (gynandro- 

 morphism) in a single individual is not uncommon. Morgan has shown 

 that sex-intergrades are rare, 1 :2,200 in the fruit fly, Drosophilia. Banta 

 found that sex-intergrades in Cladocera, a small crustacean, when once 

 established tend to produce sex-intergrades indefinitely. A race of Clado- 

 cera which for 130 generations had been breeding parthenogenically pro- 

 duced only females. In the 131st generation males and sex-intergrades 

 of many sorts appeared. Among these eight morphological secondary sex 

 characters were recognized. Practically every possible combination of 

 male and female character was seen in this generation of crustaceans. 

 Results of a similar nature have been reported by Goldschmidt, 



Sex-intergrades may be established experimentally in animals by the 

 simultaneous implantation of gonadal tissue into previously castrated 

 animals. Sand has shown that the implantation of a gonad of one sex into 



