BOOK XI. vLvii. 130-XLIX. 134 



nature, for instance ostriches and cormorants; 

 the Greek name " for the latter is derived from this 

 peculiarity.) With these races loss of the hair is 

 rare in the ease of a woman and unknown in eunuchs, 

 and never occurs in any case before sexual inter- 

 course has taken place ; and they are never bald 

 below the brainpan or the crown of the head, or round 

 the temples and the ears. Man is the only species in 

 which baldness occurs, except in cases of animals 

 born without hair, and only with human beings and 

 horses does the hair turn grey, in the former case 

 always starting at the forehead and only afterwards 

 at the back of the head. 



XLVIII. In human beings only a double-crowned Thesiculi. 

 skull occurs in some cases. The bones of the human 

 skull are flat and thin and have no marrow ; they are 

 constructed with interlockings serrated like the 

 teeth of a comb. When broken they cannot form 

 again, but the removal of a moderate piece is not 

 fatal, as its place is taken by a scar of flesh. The 

 skull of the bear is the weakest and that of the 

 parrot the hardest, as we have stated in the proper 

 place.^ 



XLIX. All blooded animals have a brain, and so Thebrain: 

 also have the sea-creatures that we have designated «^ '"Z""'^'*''"*- 

 the soft species, although they are bloodless, for 

 instance the polypus.'' Man however has the largest 

 brain in proportion to his size and the most moist 

 one, and it is the coldest of all his organs ; it is 

 wrapped in two membranes above and below, the 

 fracture of either of which is fatal. For the rest a 

 man's brain is larger than a woman's. With all human 

 beings it has no blood or veins, and in some cases no 

 fat. The learned teach that it is distinct from marrow 



515 



