300 THE DESCENT OF MAN 



but, as these generally go together, tlie distinction is often 

 overlooked. We see this distinction in those characters which 

 are transmitted through the early years of life, but are de- 

 veloped only at maturity or during old age. "We see the 

 same distinction more clearly with secondary sexual charac- 

 ters, for these are transmitted through both sexes, thoiigh 

 developed in one alone. That they are present in both 

 sexes is manifest when two species, having strongly marked 

 sexual characters, are crossed, for each transmits the char- 

 acters proper to its own male and female sex to the hybrid 

 offspring of either sex. 'The same fact is likewise manifest 

 when characters proper to the male are occasionally devel- 

 oped in the female when she grows old or becomes diseased, 

 as, for instance, when the common hen assumes the flowing 

 tail-feathers, hackles, comb, spurs, voice, arid even pug- 

 nacity of the cock. Conversely, the same thing is evident, 

 more or less plainly, with castrated males. Again, inde- 

 pendently of old age or disease, characters are occasionally 

 transferred from the male to the female, as when, in certain 

 breeds of the fowl, spurs regularly appear in the young and 

 healthy females. But in truth they are simply developed in 

 the female ; for in every breed each detail in the structure 

 of the spur is transmitted through the female to her male 

 offspring. Many oases will hereafter be given where the 

 female exhibits, more or less perfectly, characters proper 

 to the male, in whom they must have been first developed, 

 and then transferred to the female. The converse case of 

 the first development of characters in the female, and of 

 transference to the male, is less frequent; it will therefore 

 be well to give one striking instance. With bees the pollen- 

 collecting apparatus is used by the female alone for gather- 

 ing pollen for the larvae, _yet in most of the species it is 

 partially developed in the males, to whom it is quite useless^ 

 and it is perfectly developed in the males of Bombus or the 

 humble-bee." As not a single other Hymenopterous insect, 



32 M. Mliller, "Anwendung der Darwin'schen Lehre," etc., "Verh. d. n. 

 V. Jalirg." xxtx. p. 42. 



