MATING HABITS OF THE BRACHYURA. 245 



Xuttall and Merriam have made a -tudy of the copulation of 

 ticks (25). They find that there are three distinct movements 

 in copulation. The male introduces his mouth pan- into the 

 sexual orifice of the female, dilating it and probably excitin- the 

 female; then he apposes hi- <>\\n -e\ual aperture to that of the 

 female and expels the spermatophore, whose neck adheres to the 

 tip of his hypostome and is then pushed into the vagina; the 

 t movement on the part of the male is to rein traduce his 

 mouth pan- and rupture the tip of the -pcrmalophoiv. 



4. ( )ON< i.i -! >NS. 



1. In the four species of Brachyura -tudied. -e\ di-criniination 

 i- tactual. 



2. In tin I'.: chyura, tVnili/ation i- effected \\hen the female 

 ha- n enlly nunilted. 



3- Mali-- of die four species -tudied attempt to mate with 

 male- and lertili/ed female- of the -anie -pecie- but do not 

 allem|.l to male \\ith indi\idiial- of a different species. 



4. In tin- !' ichyura, the female i- not entirely pa--i\e in the 

 mo\emeiit- \\hich preeeile copulation; -he re-pond- to tactu.il 

 -limiili v:i\ en by the male. 



5. Inihe( in-- is a whole, copulation occurs at any time, 



of the moulting of the I. -male. It i- highly probable 

 thai moulting i- a necessarj toiidition for -ucce fill fertili/a- 



tion. 



<>. In the Crustacea the female i- u-ually pa i\e during th- 

 ai l of copulation. 



7. s A discrimination in the Cni-tacea i- kin.e-tln-'ic and 

 tactual. 



8. In the ( " ru-lac. a, the male- -em-rally die - i alter fertili/a- 



liou. A -mall proportion of male- li\e for -ome time. 



9. In the In-ecta. -e\ di-crimination is b\ -mell; |-'ore|'- "con- 

 ta t-o.|or sense" i> the fully de-cribin^ u rm for a lar^e decree of 



thi- discrimination. 



10. Moulting ha- not been -ho\\ n to be a nece ary forerunner 



of Fertilization in the In-ecta. 



1 I. The male- oh -ome -pi cies of In-ecta die immediately after 

 copulation. 



