REPRODUCTIVE SYSTEM. 55 



with a needle, without all the adjoining ones in- 

 stantly withdrawing their cirri; it made no difference 

 if the one touched had its operculum already closed and 

 motionless. 



Reproductive System, — Male Organs. — All the Cirri- 

 pedia which I have hitherto examined, with the exception 

 of certain species of Ibla and Scalpellum, are herma- 

 phrodite or bisexual.*" I shall so fully describe the 

 sexual relations of the several species of these two genera, 

 under their respective headings, and at the end of the 

 genus of Scalpellum, that I will not here give even an 

 abstract of the grounds on which my firm belief is based, 

 that the masculine power of certain hermaphrodite species 

 of Ibla and Scalpellum, is rendered more efficient by 

 certain parasitic males, which, from their not pairing, 

 as in all hitherto known cases, with females, but with 

 hermaphrodites, I have designated Complemental Males. 



The male organs have been well described by 

 M. Martin St. Ange, whose observations have since been 

 confirmed by R. Wagner, f The testes are small, 

 often leaden-coloured, either pear or finger-shaped, or 

 branched like club-moss, — these several forms sometimes 

 occurring in the same individual ; they coat the stomach, 

 enter the pedicels, and even the basal segments of the 

 rami of the cirri, and in some genera occupy certain 



* I am compelled to differ greatly from the account given by Prof 

 Steenstrup of the reproductive system in the Cirripedia, in his ' Untersuchun- 

 gen liber das Yorkommen des Hermaphroditismus,' ch. v, 1846; — a translation 

 of which I have seen, owing to the great kindness of Mr. Busk. Mr. Goodsir 

 has described ('Edin. NewPhil. Journal/ July 1843,) what he considers the 

 male of Balanus ; but I have seen this same parasitic creature charged with 

 ova, including larvse ! From the resemblance of the larvae to the little 

 crustacean described by Mr. Goodsir, in the same paper, as a distinct parasite, 

 I believe the latter to be the male of his so-called male Balanus, and that all 

 belong to the same species, allied to Bopyrus. This genus, as is well known, 

 is parasitic on other Crustacea ; and it is a rather interesting fact thus to 

 find, that this new parasite which is allied to Bopyrus, in structure, is like- 

 wise allied to it in habits, living attached to Cirripedia, a sub-class of the 

 Crustacea. 



f In ' Midler's Archiv,' 1834, p. 467. I have already several times 

 referred to M. Martin St. Ange's excellent Memoir, read before the Academy 

 of Sciences, and subsequently, in 1835, published separately. 



