No. 638] 



MELIBE LEONIN'A (GOULD) 



247 



wandering of the spermatozoa up the uterus, against the 

 outward current of that organ. Alder and Hancock, 

 1845, p. 25, say: 



(liUMitiy''cnpuIate duriii- ihr hreedin- >ca>nn. The (•unjoined indi- 



mntnal inii)rc.aiuUi()n is cffwted. Tlicy ivniain in lliis |..sition for 'some 

 time, but in a short iu>riod after si'paralin- -(Micrally alx.ut tlie first or 



Crozier, claims that (liromodoy'is :< l>r>i is fimctioii- 



ally herma])hr()(litie, and eftoctivo rcci piM.-al iiixMniiia- 

 tioii is practiscMl. P>ut this is not prnctiMMl ;m!.iim the 

 species Mclibe leovuio; althougli senicii may lie i)r('si'nt 

 at the same time in both genital ducts, insemination is 

 not reciprocated simultaneously. That is, in all the indi- 

 viduals examined, coitus was effected by the introduction 

 of the penis of the one mate; the i)enis of the other mate 

 was com])lct('l> witluli'nwn. Wlict lin- spcniiatozoa were 

 present in llif nicinbi'i's wliosr cxtmi.-il u'ciiital organs 



as it' Mrlihc Icniihia is protandric, a condition. ;i('<'()i'(rnig 

 to PclsciKM'i'. 1M)5, common among Kol'is, FJushi, and 

 Cltoiw liuiociini. Kliot, 1910, says: 



Moilusoa'are incapable nt MMf-iM,|MrunaiiM:: h„ii, iinlix idual ' .p.-.u-n 

 after mating. 



The writer has observcMl on I-Jolis olinn ra, at Woods 

 Hole, that one mate may staH si)a\vniiig xvliih- copulating. 

 Spermatozoa, accordinu' to Kcid. may ln' t-arried in the 

 female genitals (P'olis) foi- more than thii1\- days before 

 beinu-us.Ml. That is. dcnva-.- <l...'s not stnrt in the eggs of 

 Kohs until nfti^r deposition; Tci't i liznt ion. therefore, 

 may not occur hcforc the time of inc;ii)>nlation. Sperma- 

 tozoa are kept alive in, ami stimulated by, secretions of 

 the female genital organs, as shown by l-^liot and Kvans, 

 1908, p. 287: 



