B. IV.l THE HISTOEY OF ANIMALS. 09 



CHAPTER XI. 



1. IN some animals the sexes are distinct, in others they are 

 not so, these are said to beget and be with young by a like- 

 ness to other creatures. There is neither male nor female 

 in fixed animals, nor in testacea. In the malacia and 

 malacostraca there are male and female individuals, and in 

 all animals with feet, whether they have two or four, which 

 produce either an animal, an egg, or a worm from coition. 



2. In other kinds the sexes are either single or not single ; 

 as in all quadrupeds there is the male and female, in the 

 testacea it is not so, for as some vegetables are fertile and 

 others barren, so it is in these. Among insects and fishes 

 there are some that have no differences of this kind, as the 

 eel is neither male nor female, nor is anything produced 

 from them. 



3. But those persons who say that some eels appear to 

 have creatures like worms, of the size of a hair, attached to 

 them, speak without observation, not having seen how they 

 really are ; for none of these creatures are viviparous with- 

 out being first oviparous, none of them have ever been ob- 

 served to contain ova ; those that are viviparous have the 

 embryo attached to the uterus, and not to the abdomen, for 

 there it would be digested like food. The distinction made 

 between the so-called male and female eel that the male has 

 a larger and longer head, and that the head of the female 

 is smaller, and more rounded, is a generic, and not a sexual 

 distinction. 



4. There are some fish called epitragwe, and among fresh- 

 water fish the cyprinus and balagrus are of the same nature, 

 which never have ova or semen ; those which are firm and 

 fat, and have a small intestine, appear to be the best. 

 There are creatures, such as the testacea, and plants, which 

 beget, and produce young, but have no organ of coition ; 

 and so also in fishes the psetus, 1 erythrhinus, 2 and the ehanna. 

 All these appear to have ova. 



5. In sanguineous animals with feet that are not ovip^- 

 rous, the males are generally larger and longer lived than 



1 Pleuronectes Lingua and Rhombus, 



2 Perca marina, or Spams erithrinus.. 



