SABELLA MICROPHTHALMA VERKILL. 29! 



anterior segments, the glands have male characteristics, in the 

 central segments hermaphroditic characteristics, and in the pos- 

 terior segments the glands appear to be pure ovaries. In Sabclla 

 the ova and spermatozoa are found together throughout the 

 organ in every segment of the body posterior to the pharynx. 

 In Sabclla, no cells were found corresponding to the nurse cells 

 of Ophryotrocha. They evidently do not appear as ova were 

 observed in many stages of development. In Ophryotrocha pure 

 males and females were found besides hermaphrodites having 

 male characteristics yet containing ova, and those having female 

 characteristics yet containing spermatozoa. Sabella shows only 

 two conditions, that of a pure female and that of an hermaphro- 

 dite having both female and male characteristics. The specimens 

 appearing to be pure females could not have been hermaphro- 

 dites with the spermatozoa already developed for in the case of 

 the April ist forms, the organ as well as the whole animal -was 

 too small to have already produced spermatozoa. Where the 

 ovaries were large no spermatozoa or trace of them was found 

 in the body cavity as would have been expected if they had 

 already developed. 



Somewhat similar conditions of hermaphroditism have been 

 observed in Hesionc sicnla * by W. Bergemann. Here a long 

 gland is found differing in shape from the sex organ of Sabclla 

 but producing both ova and spermatozoa. This gland is seen 

 only between the sixth and sixteenth segments. It is not found 

 throughout the body as in the case of Sabella. Nurse cells are 

 also seen in connection with the ova which is unlike the condition 

 of Sabella. Like Hesione, the male cells in the hermaphroditic 

 organ of Sabella are generally nearer to the blood vessel as is 

 seen in Fig. 4, and usually the more mature the sex products are, 

 the nearer are they to the outside of the organ. Whether or 

 not the organ is developed from the walls of the blood vessel as 

 in the case of Hcsione, could not be determined from the material 

 at my disposal. 



VASSAR COLLEGE, 

 May 30, 1905. 



1 W. Bergemann, " Unterschungen uber die Eibildung bei Anneliden," Zeit. f. 

 U'iss. Zoo/., 1902, Bd. 73. " Ueber das spatere Schicksal der Zwitterdrusen von 

 Hesione sicula," Zool. Anz., 1902-3, Bd. 26. 



