( clxxxviii ) 



but the pilosity of certain of these joints is immensely 

 developed in 5 5 only to form a brush or " scopa " for 

 accumulating pollen. In the highest of such Bees (the Social 

 Genera) we find also paradoxical modifications of the joints 

 themselves (especially the tibiae and metatarsi of the 3rd 

 pail) which would be unintelligible, if we did not know that 

 they were employed for this particular industry. But, 

 strange to say, many of these latter characters appear in 

 both sexes, though they must be almost useless except to 

 the 9 9> H. Miiller asserts that in Bomhus the pollen-collect- 

 ing apparatus developed in the $ is transmitted from that 

 sex to the (^, and this statement greatly interested Darwin 

 who wrote * to him, " What an admirable illustration you 

 give of the transference of characters acquired by one sex — 

 namely, that of the $ of Bomhus possessing the pollen- 

 collecting appai'atus." Really, however, the transference is 

 incomplete ; for Bomhus $ does not possess what Mr. Sladen f 

 has recently shown to be an essential part of the $ and ^ 

 pollen-collecting apparatus, viz. the so-called "auricle," or 

 dentiform process which arms the base of the metatarsus. 

 The case of the Hive Bee Apis is more curious still. For 

 here neither the Male nor the Female leg, but only that of 

 the Worker, possesses an auricle, or a true pollen-basket 

 (corbicula). In this Genus the Division of Labour has been 

 carried further than in Bomhus. Its Queen is, as Mr. Sladen 

 puts it, a " mere machine for laying eggs," and never gathers 

 pollen at all. Her legs, which are piactically identical with 

 those of the male, are in fact, just as in the latter sex, a 

 fraud! They have the general appearance of a "pollen- 

 collecting apparatus," but lack details which are essential 

 to it. The Workers, however, have such an apparatus, 

 differing hardly at all from that of Bomhus : which, being 

 normally sterile, they cannot have developed for themselves, 

 but must have received from their parents (Drones and Queens). 

 From these facts a curious conclusion appears to follows 

 namely that (a) a structure was developed in the $ 9) ^^^ after- 

 wards transmitted in part to the (^ c^, of the stock from which 



* More Letters of C. Darivin, Vol. II., p. 97. 

 t The Humble Bee, p. 22. 



