No. 632] SECONDARY SEXUAL CHARACTERS 237 



In the Canadian Naturalist for May, 1919 (Vol. 

 XXXIII, No. 2), there is a description of another "her- 

 maphrodite" lobster. In reply to a letter of inquiry that 

 I sent to Mr. A. P. Wright, he states that the lobster was 

 sent to him by Mr. Halkett and that the animal is male on 

 the left side and female on the right side. There is an 

 ovary on one side and a testis on the other. These three 

 cases appear to differ from the preceding cases and sug- 

 gest a direct comparison with the bilateral gynandro- 

 morphs of insects. It is quite possible that they owe 

 their origin to some similar chromosome "elimination" 

 in the course of development, but it should not be for- 

 gotten that sex-chromosomes have not been reported in 

 the lobster, although the cytology of the spermatozoa has 

 been often examined. 



Another decapod, Gebia major, has been shown by 

 Ishikawa to be hermaphroditic. The anterior end of the 

 testes produces sperm and the posterior eggs. A pair of 

 ducts leads from each part to the exterior. Such indi- 

 viduals appear to function only as males. Spitschakoff 

 found in a crab, Lysmata seticaudata, that both ovaries 

 and testes are present with their ducts and external geni- 

 tal pores on the third and fifth pairs of legs. The an- 

 terior end of the gonad functions as ovary and the poste- 

 rior as testes, which is the reverse relation from that of 

 Gebia. 



In crayfish belonging to the genus Parastacus, von 

 Martens/ 1870, von Hiring, Faxon, 1898, and Loniib.-rir. 

 1898, have described genital pores on the third and fifth 

 pairs of appendages. Lonnberg has dissected some of 

 these individuals. He finds testes in some of them, 

 ovaries in others, but in both cases there are two pairs of 

 ducts lead to the genital pores on the third and fifth 

 pairs of legs. Here there is no true hermaphroditism, 

 but on the contrary separate sexes. Nevertheless the 

 ducts characteristic of the males and females m other 

 species with separate sexes are both present in all indi- 

 viduals of Parastacus. 



