PARTS CONCERNED IN REPRODUCTION. 



4. In conclusion, a few observations may be made on 

 the relations of the sex to the individual. 



If this term individual be applied to every isolated or- 

 ganism, then it is only in cases in which as in the higher 

 species no process of detachment of gemmae is interposed, 

 at any period of the life-history, so as to interfere with the 

 integration into a single body of the successive phases of 

 organization, that the character of sexuality can attach to 

 every individual of the species. On a first view, indeed, 

 its limits appear even more restricted, for, though in the 

 higher animals except in circumstances of immaturity, or 

 of mutilation, or other abnormality all the individuals 

 have true sexual powers, yet, in certain families of the 

 Invertebrata as Bees and Termites, among insects the re- 

 productive faculty is not diffused over the whole species, 

 the majority being destitute of all power, either of impreg- 

 nation, or conception, and hence termed neuters, as being 

 neither males nor females. This sterility, however, is rather 

 functional than organic, the so-called neuters being, in fact, 

 females, in which the reproductive organs have remained in 

 a rudimentary condition. 



Generally in the animal kingdom, the development is 

 one-sided, the same indvidual not producing both sexual 

 elements. In the normal condition of the higher animals, 

 we never find the sexes united, each individual being 

 either simply male or simply female. This applies uni- 

 versally to Vertebrata, except as a rare monstrosity.* 

 It applies also very generally to the typical Articulata, 

 except in aberrant orders, as the Cirripedia, but in the 

 vermiform tribes, and in the sub-kingdom of Mollusca, the 

 union of the sexes, by what is termed a hermaphrodite or 

 bi-sexual arrangement, is common enough. 



* It seems to occur more frequently in fishes than in any of the higher 

 classes, and is said to be a normal phenomenon in the perch. (Dufosse 

 Annales des Sciences Naturelles, 1857.) 



M 



