48 
MOMCA TAYLOR. 
(e) Nervous System. 
(1) The brain is at first solid and is hollowed out secondarily. 
(2) Three main divisions of the braiu can be distinguished 
in Stage 21. 
(3) There is no cranial flexure until Stage 24, and there- 
fore no reason for assuming that the infundibulum is the 
morphologically anterior end of the brain. 
(4) Sagittal sections through the brain at different stages 
show the usual Teleostean characters. 
(5) The cerebellum is late in developing and goes on grow- 
ing after metamorphosis. 
(6) The optic lobes of the mature braiu are relatively 
smaller than in the developing one. The mid-brain of the 
adult is the least conspicuous part. 
(7) The mature brain is elongate, as also are the olfac- 
tory and optic nerves, the divisions well separated off. 
Literature. 
1. 1911. Agar, W. E. — “ The Spermatogenesis of Lepidosireii para- 
doxa,” ‘Quart. Journ. Micr. Sci.,’ N.s., vol. 57, Part 1. 
2. 1907. Assheton, Pichard. — “The Development of Gymnarchus 
niloticus,” in ‘The "Work of John Samuel Budget!,’ Cambridge. 
3. 1909. Goodrich, E. S. — ‘ A Treatise on Zoology,’ edited by Sir Pay 
Lankester. 
4 . 1901. Kerr, J. Graham. — “The Development of Lepidosiren 
paradoxa,” Part II, ‘ Quart. Journ. Micr. Sci.,’ N.s., vol. 178, p. 5. 
5. 1900. Kerr, J. Graham. — “The External Features in the Develop- 
ment of Lepidosiren paradoxa,” ‘Phil. Trans. Poy. Soc. 
Lond.,’ Ser. b, vol. cxcii. 
6. 1909-10. Kerr, J. Graham. — ‘ Proc. Poy. Phys. Soc. Edin.,’ vol. 
xviii. No. 2. 
7. 1903. Nicholas, A. — “ Pech. sur le development du pancreas, du 
foie et de la rate cliez la Sterlet,” ‘ Arch, de Biol.,’ t. xx. 
8 . 1902. Piper, H. — “ Die Entwicklung von Magen, Duodenum, etc., bei 
Amia calva,” ‘Arch. Anat. Phys. Anat. Abt. SuppL’ 
9. 1912. Pegan, C. Tate. — ‘Ann. and Mag. Nat. Hist.,’ ser. 8, vol. ix. 
10. 1903. Schauinsland, H. — “ Beitriige z. Entw. der Wirbeltiere : 
Callorhynchus,” ‘ Zoologica,’ Heft 39. 
