44 



VARIATION 



belongs to Mr. Richardson, and was examined by Professor Bateson as 

 closely as was possible without removing the hairs, to which the owner 

 objected. It is well known that supernumerary wings may arise with the 

 normal number of legs. In this case the closest examination failed to reveal 



even a rudimentary leg, and there was cer- 

 tainly " no empty socket or other suggestion 

 that the rest of the leg had been lost." 



4. Specimen of Palinurus penicillatus with 

 an " antenna-like flagellum growing up from 

 the surface of the (left) eye." 



5. The female crayfish has normally a pair 

 of oviducal openings on the bases of the ante- 

 penultimate pair of walking legs. This speci- 

 men possessed in addition a pair also on the 



p -- showing irreg ? ar s f ^ entati r, 



6. Another specimen, also of the crayfish, 

 possesses an extra pair of oviducal openings, as in the last, except that they 

 were placed on the last pair of legs, skipping the penultimate. It is note- 

 worthy that this is the normal position for the sexual organs of the male, 

 except that the openings were placed in their own proper position on the leg 

 and not " at the posterior surface of the joint as the male openings are." 



7. Bateson himself examined 586 female crayfish for abnormalities of 

 oviducal openings. Of this number he found 563 were normal and 23 

 abnormal, as follows : 



1. Extra oviducal opening on left penultimate leg 7 



2. Extra oviducal opening on right penultimate leg . . . . 10 



3. Extra oviducal opening on both penultimate legs .... i 



4. Extra oviducal opening on both penultimate and last legs . i 



5. Single oviducal opening on left side only 3 



6. Single oviducal opening on right side only i 



Total abnormal specimens 23 



Bateson reports but one abnormal specimen out of 7 1 4 males examined 

 by him, and this abnormality consisted in the absence of a generative open- 

 ing on the right side. 



8. Among earthworms will be found many cases of imperfect segmenta- 

 tion, showing more rings on one side than upon the other, often suggesting 

 a spiral rather than a series of rings. Great irregularity is also found in the 

 position of generative openings, as to whether paired or single, 1 although 

 the male parts are always posterior to the female, whatever the number of 

 the ring on which either is borne. 



Cervical fistulae and auricular appendages in mammals. 2 

 Cervical fistulae are openings in the neck, occurring singly or in 

 pairs and located anywhere from the median line backward as 



1 Bateson, Materials, etc., pp. 156-166. * I hid. pp. 174-180. 



