ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 295 



Role of Vagi in Development of Sympathetic Nervous System.* 

 Albert Kuntz has made observations on embryos of the pig which lead 

 him to conclude that the primordia of the myenteric and submucous 

 plexuses, the pulmonary plexuses, and the cardiac plexus, have their 

 origin in nervous elements which migrate from the vagus ganglia and 

 the walls of the hind brain along the paths of the vagus nerves. 



Cranial Nerves of Pike.t — B. A. Panschin comes to the following- 

 conclusions. The olfactory is a visceral-sensory nerve, whose segmental 

 nature is obscure. The optic presents no peculiarity. The oculomotor 

 is a somatic-motor nerve, except as regards a new ciliary ramus of 

 unknown nature. The trochlear and abducens are purely somatic- 

 motor and present no peculiarity. The trigeminus i. is an incomplete 

 segmental nerve, somatic-sensory in nature, probably associated with the 

 first post-oral gill-cleft. It is to be distinguished from the complete 

 segmental nerve trigeminus ii., associated with the prse-spiracular cleft. 

 In spite of the disappearance of the spiracle in Teleosteans, the facial is 

 its complete segmental nerve. The glossopharyngeal is an incomplete 

 segmental nerve of the first gill-cleft : it has lost two branches. In 

 the vagus group are included two non-segmental and at least three 

 segmental nerves. The acustico-lateralis complex has three ganglia. 



Development of Alimentary Canal in Lepidosiren and Proto- 

 pterus.J — J- Graham Kerr gives the following summary of the results of 

 his investigation. The fore-gut first becomes folded off from the main 

 mass of yolk-cells, The pyloric valve arises by the hind end of the 

 fore-gut being pushed back into the cavity of the mid-gut. The main 

 mass of yolk-cells becomes gradually " modelled " into a spirally coiled 

 intestinal rudiment. The main part of the buccal lining is developed 

 in situ from large yolk-cells. 



The part of the ventral side of the head, on which are the olfactory 

 rudiments, becomes enclosed in the buccal cavity by the development of 

 the upper lips and by the forward growth of the lower jaw. The 

 olfactory opening becomes divided into anterior and posterior nares by 

 the apposition and fusion of the intermediate portion of its lips. 



The thyroid arises as a solid downgrowth from the bucco-pharyngeal 

 floor, which gradually becomes cut off from behind forwards. The 

 tongue is a primary tongue like that of Urodeles, but without gland- 

 field. The pancreas arises from a dorsal and two ventral rudiments. 



The lung arises from a solid mid-ventral rudiment. When the lung 

 becomes bilobed, the (actual) right lobe is for a time small in size as 

 compared with its fellow. Complicated torsional processes take place 

 during the development of the lung. Through the dorsal mesentery 

 becoming partially merged in the splanchnoccele roof, the lungs come 

 to be outside the splanchnoccele. The general facts of lung develop- 

 ment go to support the view that the lung of Polypterus shows a persist- 

 ence of the condition ancestral to that of Dipnoi and Actinopterygii. 



* Anat. Anzeig., xxxv. (1909) pp. 381-90 (4 figs.). 



t Tom. cit , pp. 443-67 (7 figs.). 



t Journ. Quart. Micr. Sci., liv. (1910) pp. 483-518 (13 figs.). 



