206 Secondary Male Characters in a Pheasant 



case of the tail feathers. In the tail (as far as can be ascertained owing 

 to the unfortunate absence of the two central feathers) it is the outer 

 half of each feather that has assumed the male type of plumage (PL XII, 

 fig. 7). In other words instead of the tail as a whole showing a 

 division into a male half and a female half, each feather of the tail 

 shows male colouring and pattern on the outer or less covered half, 

 and female colouring and pattern on the inner or more covered half. 



Examination of the internal organs. 



Careful dissection shows the presence of a well developed oviduct 

 opening into the cloaca in the usual situation on the left side. 



In the situation of the ovary (though somewhat nearer to the 

 middle line) a sex gland was found roughly f inch long by J inch 

 wdde, nodular on the surface and in parts deeply pigmented (PI. XIII, 

 fig. 10). No trace of a sex gland could be found on the right side. 

 Microscopical examination of this gland shows actively growing areas 

 of tubular gland structure in some of which bodies like spermatozoa 

 can be detected; the acini are lined by columnar epithelium (PI. XIII, 

 fig. 12). Smaller areas of fibrous tissue with much pigment and degene- 

 rating cysts are found in another part while a third portion resembles 

 in structure the cortical part of the suprarenal gland. This sex gland 

 is in fact an ovo-testis, and from the degenerating pigmented condition 

 of the ovarian portion (PI. XIII, fig. 11), and the actively growing 

 character of the testicular portion, it seems probable that it functioned 

 originally as a female gland, and that the ovarian portion sub- 

 sequently atrophied while the tubular gland or male portion then 

 became functionally active. 



Remarks. The assumption of male secondary characters on one 

 side of the body only in this case presents considerable difficulty when 

 we attempt to apply the usual hormonic explanation to the development 

 of these characters. And yet the facts already established compel us 

 to accept the hormonic explanation as a partial although not a complete 

 solution of the problem. 



The older experiments on the results of castration in the male 

 animal and the more recent observations of Marshall, Shattock, and 

 others on birds and animals conclusively show that with the removal 

 of all traces of the sex gland in the male the secondary male characters 

 fail to appear if they have not already begun to grow, or undergo a 



