SEXUAL RELATIONS. 27 



are lost or have coalesced with the others ; so that within the 

 same sub-class all seventeen segments of the archetype 

 have almost disappeared. 



It may be asked how I know that the several above 

 described rudimentary epizoons are really the males of the 

 Cirripedes to which they are attached. Even if the whole 

 course of the metamorphoses had not been known in three 

 of the cases, the mere fact of these epizoons being cemented 

 by the three terminal segments of their peculiar, pupal 

 antennae, would have been sufficient to have shown that 

 they belonged to the class of Cirripedes. In nearly every 

 case, I was able to demonstrate, and not in one or two but 

 in many specimens, that these epizoons were males ; and as 

 in several instances the spermatozoa were developed, and 

 as, notwithstanding, in no instance was there a vestige of ova 

 or ovaria, it may safely be concluded that they were not 

 hermaphrodites, and therefore required females of some 

 kind. If these epizoic Cirripedes had been independent 

 animals, as they all belong to the same sub-class, and all have 

 such peculiar habits, it might have been expected that they 

 would have shown some special affinity towards each other; 

 but this is not the case ; the epizoon of Ibla is more nearly 

 related to Ibla, and the epizoon of Scalpellum more nearly 

 related to Scalpellum, than are these epizoons to each other. 

 If the several epizoons were classed by themselves, they 

 would be grouped in divisions, corresponding with those of 

 the Cirripedes on which they are attached, which is just 

 what might have been expected if these latter were their 

 females. There are, also, many special relations between 

 the male epizoons and the Cirripedes to which they are 

 attached ; thus, the mouth of the epizoon of Ibla, is so like 

 the mouth of Ibla, which is peculiar in several respects, 

 that I should easily have recognised it as belonging to a 

 member of that genus. Scalpellum villosum is remarkable 

 as one out of only two or three members of the whole 

 Family, which is destitute of caudal appendages, so is its 

 male epizoon ; again, S. villosum is unusually spinose, so is 

 its male epizoon ; on the other hand, /Scalpellum ornatum 

 is remarkably smooth, so is its male epizoon ; and I could 

 give other similar instances. Will it be believed that these 



