342 



Me. f. B. BEDDABD ON EARTHWORMS 



[Apr. 16, 



spermatophores of Tahifex aud some of its allies are motile. Mauy 

 observers have noted this fact. Thus one of the first, if not the 

 first, to note the point, Jules d'Udekem \ remarked that " ils font 

 quel'quefois plusieurs circonvolutions." Before him Budge " had 

 described these structures in Tubifex or in Limnodrilus; and though 

 stating that they bear " cilia " (which are of course the ends of the 

 individual spermatozoa) did not comment upon their motility as a 

 whole. Gegenbaur in his ' Grrundziige ' records the movement of 

 these spermatophores. Claparede ' observed that " ils agitent leurs 

 cils longs a la maniere des Dicyema, mais ne chaugent que pen de 

 place. Leur pouvoir de locomotion parait assez hmite." On the 

 other hand, in Psammoryctes umhellifer (or P. harbatus as it appar- 

 ently should be properly called) Lankester ' noted a movement of 

 great rapidity which resulted in the description of " a figure of 

 eight passing and repassing on the same track."' The enormous 

 quantity of the spermatophores within the spermathecal sac is ver}- 

 noteworthy and a difficult fact to understand. It must be borne in 

 mind, however, that Poh/toreutus produces a considerable quantity 

 of eggs, while the Tubificidse, in whose spermathecse there is but 

 room for a few spermatophores. have large-yolked and few eggs. 



Text-fig. 85. 



Spermatojjhores of Pol//toreutus magiknsis, greatly magnified. 

 A, fully mature spermatojiliore ; B, an emptj case. 



My original drawings of the spermatophores of Polytorentas 

 marjilensis do not do entire justice to their remarkable form in that 

 species, though the sketch given is quite an accurate representation 

 of a spermatophere. I therefore exhibit some sketches (text- 

 fig. 85) which will enable the spermatophores of the two species 



1 " Histoire naturelle du Tnbifex des Euisseaux," Mem. cour. et Mem. des Sav. 

 etrang. Acad. Belg. sxvi. p. 26. 



* " Ueber die Gesclileclitsorgane von Tnbifex riviilorum," Arch. f. Naturg. xvi. 

 1850, p. 7. 



' ^00. cit. t ioc. cit. 



