2i8 Nctes. iv. I — 2. 



♦ 



8. All yertebrata have a mesentery, with the exception of the lamprey, the carp, and 

 some other fishes, and even these have it in their embryonic stage. As to the omentum; 

 of. iv. 3, Note 3 ; as to diaphragm^ cf. iii. 10, Note I. 



9. Cf. iii. 3, Note 5. ^ 



(Ch. 2.) r. In certain Ophidia the gall-bladder is in fact completely separated from the 

 liver and lies close to the pylorus. This is so in all the serpents that have the tongue 

 enclosed in a sheath {Duvernoy,.Ann. d. Sc. Nat. xxx. 12;/). A similar condition is found 

 in some fishes {Owen, Led. on Comp. An. ii. 243), among others in the Lophius, the 

 Swordfish and the Muraena ; all of whicn are elsewhere [,H. A. ii. 15, 14) enumerated as 

 ej^amples of this structure. Probably this peculiar arrangement, has reference to the 

 long narrow shape of the animals, and exists for convenience of packing. * 



2. As to lower stomach, cf. ii. 3, Note 6 ; iii. 14, Note 31. The exact meaning of this 

 passage is doubtful. I understand, however, A. to mean that the bile is in all cases 



. discharged into the intestine at a point below the upper or true stomach. 



3. Fishes are very rarely without a gall-bladder, though there are some few exceptions, 

 e.g. sawfish, lamprey, and basking-shark. 



.4. The Amia appears to be the Scomber Sarda af Cuvier. This fish abounds in the 

 Mediterranean. Like *the tunny, bonito, and sundry other Scombridse, it is remarkable 

 for the extreme length and slenderness of its gall-bladder. Cuvier, Reg. Anim. ii. 199, 

 and Owen, Lect. ii. 244. 



5. " Therefore," i.e. inasmuch as the bile is always discharged into the intestine as an 

 excrement. The writer alluded to is Plato in the TimcBus. Cf. Joaveifs Transl. ii. 564. 



6. Elsewhere {H. A, ii. 15, 11) the elephant is said to present this structure; and 

 correctly so stated (cf. Owen, Vert. iii. 480). Whether a similar structure exists in the 

 camel I do not know. It has, . however, no gall-bladder ; and the under surface of its 

 liver is marked by numerous irregular and intersecting fissures {Floiuer's Lect., Med. Times, 

 1872, p. 371). Possibly it may have been these fissures that were taken by Aristotle, or 

 his informant, to be dilated bile-vessels. • 



7. A. is correct in this enumeration of animals that have no gall-bladder, with- the 

 exception of the seal. The Phoca vitulina has a gall-bladder ; but it may possibly, 

 though improbably, be that the Phoca irtbnachus, which was the species best known 

 to the ancients (Cuvier, Regne An. i. 169)^ is without one, as Frantzius suggests. 



8. The gall-bladder is sometimes present, sometimes absent in giraffes {Owen, Joly) \ 

 in the apteryx and bittern {Owen); in the guinea-fowl, etc. It is especially variable, 

 as A. rightly says, in the different species of Mus [Cuvier, Lemons, iv. 36). In man a 

 congenital absence of the gall-bladder hixs been noticed in rare instances {Rokitansky, ii. . 

 155 ; Phil. Trans. 1749). This however could not be known to A., who says moreover 

 {H. A. i. 17, 10) that most men are without a gall-bladder. 'If, as I have suggested 

 (i. 5, Note l), A. examined aborted human embryos, h^ might easily have been led to this 

 erroneous opinion. For the gall-bladder is not developed at all until the third month, 

 at a time when the liver almost entirely fills the abdominal cavity. 



9. A similar statement is made in the Hist. An. (i. 17, 11) ; where also we learn that 

 the knowledge of the facts was obtained by observation of sacrificial victiriis, a source of 

 anatomical information elsewhere referred to (cf. iii. 4, Note 37). Chalcis was, it may be 

 noted, the place to which A. retired when he quitted Athens, and where he finished 

 his life. 



10. This clearly professes to be no more than an h Jiriori notion, and not to be 

 founded on actual dissection. . 



11. When an animal's body is opened some time after death, the parts near the gall- 



