222 KATHARINE FOOT AND E. C. STROBELL. 



"THE SECONDARY SEXUAL CHARACTERS." 



"In the most highly evolved stages in the evolution of sex a 

 new kind of character makes its appearance. This is the 

 secondary sexual character. In most cases such characters are 

 more elaborate in the male, but occasionally in the female. 

 They are the most astonishing thing that nature has done: 

 brilliant colors, plumes, combs, wattles, and spurs, scent glands 

 (pleasant and unpleasant) ; red spots, yellow spots, green spots, 

 topknots and tails, horns, lanterns for the dark, songs, howlings, 

 dances and tourneys a medley of odds and ends" (p. 26). 



If we are to discard Hunter's classification, because it is found 

 difficult to determine into which class some of the characters 

 rightly belong, we should have to be dissatisfied with many 

 classifications that are thoroughly well established. 



If we limit the term "primary sexual characters" to the repro- 

 ductive glands, it offers an escape from the difficulties in classify- 

 ing the prehension organs, as Darwin has pointed out; but it 

 would seem that greater difficulties are met by refusing to place 

 the intromittent organ in the same group with the reproductive 

 glands; and placing it in the group with characters so far 

 removed from "direct connection with the act of reproduction" 

 as, for example, Morgan's list of secondary sexual characters, 

 "brilliant colors, plumes, combs, wattles, and spurs, scent glands 

 (pleasant and unpleasant) ; red spots, yellow spots, green spots, 

 topknots and tails, horns, lanterns for the dark, songs, howlings, 

 dances and tourneys a medley of odds and ends." The intro- 

 mittent organ is not only "directly connected with the act of 

 reproduction"; but it is as much a part of the sex of the indi- 

 vidual as the reproductive glands themselves. Any one of the 

 characters in Morgan's entire list of male secondary sexual 

 characters could appear in the female without changing her sex; 

 but the intromittent organ is as clearly indicative of the sex as 

 are the reproductive glands themselves. 



If a definite chromosome carries the factors for determining 

 sex and it therefore carries the factors for the reproductive 

 glands, it would seem logical to suppose that the chromosome 

 carrying the factors necessary for the development of the male re- 

 productive glands would also carry the factors necessary for the 



