398 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 54. 



5. Alteration of external sexual characters. 



SECONDARY SEXUAL CHARACTEES. 



a. Color of clypeus. — Smith and Hamin (1914) have added another 

 record of the tendency of clypeus to assume the color of the opposite 

 sex. A stylopised female Andrena chrysosceles Kirby was found by 

 Mr. Hamm at Sandford, near Oxford, England, which had the 

 clypeus colored as in the male. An illustration is presented in their 

 plate 35 of the normal faces of each sex and of the face of this para- 

 sitized female. The authors are in error, however, when on page 453 

 they write : " We have already seen that no other observer has appar- 

 ently described the effect of Stylops on the clypeus coloration of cer- 

 tain Andrena, noticed by Perez, until we came across the case of A. 

 chrysosceles published here." It is hardly conceivable how thej' 

 could have made such a statement when they claim to have consulted 

 the writer's Revision of the Strepsiptera (Bulletin 66), which on 

 page 33 cites three such instances under the same heading as above. 



The same writers also mention cases of Andrena lahialis furnished 

 them by Messrs. Perez and Perkins, consisting of four female bees 

 parasitized by females, which show the faces colored as in the 

 males, and a male bee parasitized by a male Stylops which shows a 

 marked reduction of the white color on the face. 



A specimen of male Panweginus calif omicus from Los Angeles, 

 Califoyiia, is at hand with the yellow on the clypeus reduced to a 

 narrow median line, 



d. Antennae. — Smith and Hamm (1914) found no evidence of 

 modification due to stylopization in the antennae of Andrena 

 nigroaenea. 



e. Organs of work. — Smith and Hamm (1914), in their studies 

 of parasitized Andrena nigroaenea, found "that as a result of 

 stylopisation the m.ale does not acquire in any degree the scopa of 

 the female, while the scopa of the female is always to some extent 

 reduced in size by the action of stylopisation." 



PRIMARY SEXUAL CHARACTERS. 



a. Ovipositor. — Smith and Hamm (1914) were unable to find any 

 modification in this organ in stylopised Andrena nigroaenea. 



h. Male copulatory organs. — Smith and Hamm (1914) were unable 

 to find any modification in these organs in stylopised Andrena 

 nigroaenea. 



7. Injury to internal organs. 



a. Alimentary system. — Perkins (1892) found no effect upon the 

 digestive tract of Andrena nana Kirby and Andrena wUkella Kirby. 



e. Reproduction. — Perkins (1892) writes: "In all the male speci- 

 mens that I dissected the vesiculae seminules were found to contain 



