AND THEIK FUNCTIONS. 171 



He did not believe that fishes had any visible external 

 passages from the generative organs.* In cartilaginous 

 fishes, the genital passages open into a cloaca, but in most 

 bony fishes the external passages from the generative organs 

 are visible behind the anus, and may be readily seen in the 

 bass, gurnard, silurus, and salmon. 



Aristotle's descriptions of the female generative organs 

 of the invertebrata are sometimes very difficult to under- 

 stand at all. They were probably based on dissections, but 

 it is almost certain that the parts were not dissected out at 

 all clearly. 



He misunderstood the arrangement of the female organs 

 of crustaceans in much the same way as he misunderstood 

 the arrangement of the male organs, for he speaks of the 

 oviducts extending along the intestine and opening out- 

 wards somewhere on the telson.t 



The female octopus, he says, has an woV, meaning 

 probably the ovarium, uneven outside, smooth and white 

 inside, and containing a very large quantity of eggs ; in 

 Sepia, he says, there are two such ovaria, also containing 

 many white eggs.+ This appears to be his meaning, but it 

 is difficult to understand, for the eggs are contained in 

 ovisacs projecting from the interior surface of the ovarium, 

 and no cephalopod seems to have more than one ovarium ; 

 Sepia has one oviduct while Octopus has two. 



There are many other statements about the generative 

 parts of these and other invertebrata, and, among these, 

 may be specially mentioned the one in which he correctly 

 records the number of the ovaria in Echinus, for he says 

 that they are five in number. § 



He gives some information, chiefly mH. A. ii. c. 3, about 

 the teats of various animals. He states correctly that the 

 elephant has two teats between its fore legs, and that the 

 camel and leopardess have four each, but gives the number 

 of teats in the bear as four instead of six, and that in the 

 lioness as two instead of four. 



He shows that he had examined the dolphin carefully, 

 for he says that this animal has two mammae, not in its an- 

 terior part but near its genitals, that it has no visible teats, but 

 two ducts, as it were, one on each side, from which the 

 milk flows, being sucked by the young ones as they follow 

 their mother, and that this had been clearly seen by some 



- H. A. ii. c. 9, s. 2. f Ibid. iv. c. 2, ss. 12 and 13. 



X Ibid. iv. c. 1) ss. 13 and 14. § Ibid. iv. c. 5, s. 5. 



