SECONDARY SEXUAL CHARACTERS OF CRAYFISHES. 267 



of the female at the base of the third walking legs. A dissection 

 revealed that there were fully developed ovaries and oviducts on 

 both sides and a small testis with a -perm duct on the right -ide. 



Hay concludes that in the genus Cambarns hermaphroditic in- 

 dividuals are females "which owing to some ambiguity of t In- 

 formative cells in the embryo have de\ i t> a greater or le 

 degree the characters of the opposite sex. The condition is a \ vry 

 rare one and i- u-ually -hown in the external organs only". . . . 

 " Hermaphroditism i- as uncommon in Astacus as in Cum/urns. 

 Among the I'ara-t.n id.e the condition of apparent hermaphrodit- 

 i-m seems to U- e-tabli-hed in the genu- /' It may 

 also 1'e found in ait is rare or altogether wanting in 

 otlier genera. " 



Ortmaii [905 ' ; >- nhi-ii ti\e additional cases in the genus 

 ibnrns, four colle.ie-1 by himself and one 1>\ I-]. M. \Yilliam-on. 



1 li- !ir-t case was< >nr >f < r ns obscnru^ which had as female 



-.ual charai tcr- the female t>i"- <\ law. a detinite 

 hut -mall amiulii- an<l no ho. .k- on the third walking legs. I 

 spe< imen had. ho\\.-\er. the genital opening- of the male al the 

 6 <>f the lifth walki: tnd the first and -f.-Mul alxloniinal 



ap|)eii' < leal 1\ < if the male type. 



The -ennui -p-< inuMi \\ one of Cum/Mir. v. liich 



had not <ml\- t he aiiiuilu> and the genital openin in- ft-nia It- 



hut al-o copulatoiA hook- on i he third leg (a male haracterisl 

 The alidominal appendage- Wi I e .1! ui-'i'inal Inn full--i/ed ami 

 male-like. 1'hc -pecimeii \\a- inter|)reted as deing a female 

 with the lull Inn not -pi-ciiic <le\ elopni.-m of male . n-gan-. 



In the third case the -pecinien ;rt<uii< \\a- a func- 



tional female. 71 nun. long with .ttached to the alxlomen. 



It -1 lowed the full equipment of SCCOndarj -e\ual character- of t he 

 fcniali- and in addition a pair of hook- at the base of th.- third 

 walking 1 j 



The fourth individual, al-o 'men of Ciunhnrns Imrtoni 



(48 mm. long', had female i law-, a well-developrd aiintllus and 

 the second abdominal appendage- of the female. The tl-lial 

 hooks at the l>a-e of the third walking keg- were lacking. 'I 

 male secondary sexual character^ were shown in the genital open- 

 ings at the l>a-e of the fifth walking legs and in the full develop- 

 ment of the male tir-t abdominal appemlao - 



