1902.] VARIATION IN THE NORWAY LOBSTER. 9 



Mr. Bateson has, however, placed on record several cases of 

 females of Astacus Jiuviatilis with additional oviducal apertvires, 

 but their degree of frequency was not nearly so great as that of 

 the abnormal spermatic apertures in Neplirops. After citing 

 Desmarest's observation of a female Astacus with oviducal 

 apertures on both the antepenultimate and penviltimate legs, to 

 each of which the oviducts branched, he describes several cases 

 that he has himself observed. Among 583 female Astaci he 

 records 23 which were abnormal in regard to the genital aper- 

 tures, 17 having an opening on one of the fourth legs, one with 

 an opening on each of the fourth legs, one with one opening on 

 each of the fourth and fifth legs (in each case in addition to the 

 normal openings), and four in which one of the normal openings 

 was wanting. The oviducts in most cases gave ofi" branches to 

 the abnormal openings as in Desmarest's specimen. Mr. Bateson 

 cites Dr. Benham's observation on a female crayfish which had a 

 pair of supernumerary openings on the fifth legs but none on the 

 fourth. Out of 714 males that Mr. Bateson examined, one was 

 abnormal in having no spermatic aperture on the right side. No 

 cases of additional spermatic apertures are recorded for Astacus. 



The above-described variations in Nephroids would appear to 

 have some bearing on the supposed cases of hermaphroditism 

 among the Astacidte. La Yalette St. George has described a 

 specimen of Astacus Jiuviatilis, in its external characters a male, 

 but with what appeared to be a hermaphrodite gland. Bergendal 

 in two papers has recorded his observations on females of Astacus 

 Jiuviatilis in which the appendages of the first abdominal somite 

 were modified as in the male ; and Faxon has cited other cases of 

 pai-tial or complete hermaphroditism. But it is only those cases 

 where the evidence of hermaphroditism is supplied by the exist- 

 ence of apertures situated as in one sex, in animals which in many 

 characters resemble the other sex, which specially concern the 

 subject of this paper. 



In his ' Revision of the Astacidse ' Faxon gives an account of a 

 specimen of Camharus p^opinquus, which appears to have been an 

 undoubted female, for ovarian eggs were found on dissecting it. 

 The external chai-acters, including the condition of the appendages 

 of the first and second abdominal somites, were also those of the 

 female, with the exception of the position of the genital apertures, 

 which were on the last pair of thoracic legs — i. e., in the position 

 typical of the male. 



Lonnberg states that he believes he has seen rudimentary 

 genital ducts passing to the third pair of thoracic legs in two 

 specimens of Gambarus fallax, but owing to their state of preser- 

 vation he is not positive. 



Yon Martens has long ago recorded the presence of additional 

 apertures on the bases of the antepenviltimate legs in certain 

 male specimens of Chei'aps 2^6issii, Astacus pilimanus, and 

 A. brasiliensis, the two latter of which are now included in 

 Huxley's genus Parastaciis. 



Von Ihering describes these apertures which occur in all the 



