662 SUMMARY OF CURRENT RESEARCHES RELATING TO 



marked layers. At 11 cm. striations appear in the muscle fibres, while 

 at the same time sarcostjles may be observed in them when they are 

 viewed in cross section. The glands of the oesophagus at this level in 

 pigs appear in embryos of about 21 cm. long. They originate as down- 

 growths of the mucosal epithelium which pass through the muscle 

 bundles of the muscularis mucosae into the deeper layers of the suIj- 

 mucosa. These first downgrowths have a double row of low cubical 

 cells. From the divisions at their ends are formed the primitive alveoli^ 

 while from the inner row of cells of these acini the mucous cells which 

 push the outer row off towards the l)asement membrane are derived. 



Mouth-cavity and Pharynx of Birds and their Glands.* — K. 



Heidrich gives a very detailed description of the macroscopic and 

 microscopic characters of the mouth and pharynx of birds. The following, 

 points out of many may be noted regarding the glands of this region 

 in the domestic fowl. These structures are very abundant in the sub- 

 mucosa. In the roof of the palate in front of the nares occurs the paired 

 gl. maxillaris monostomatica ; on both sides of the narial opening, the 

 median (with about 120 openings), and the lateral (with about 85 open- 

 ings) gl. palatinse ; on the roof of the jaws on both sides of the infundi- 

 bular clefts, the gl. sphenopterygoidese (with about 50 openings) ; on 

 the floor of the mouth-cavity in the angle of the two rami the paired 

 gl. submaxillaris anterior (with about 10-15 openings) ; behind this the 

 gl. submaxillaris posterior in three parts ; within the tongue the gl. 

 Hnguales anteriores in two parts ; at its base the gl. linguales posteriores 

 (with about 100 openings) ; lateral to the glottis the gl. cricoarytsenoid^ ;: 

 and in the angle of the mouth the gl. angularis ovis monostomatica. 

 All the salivary glands of the mouth and pharynx are pure mucous 

 glands ; granule-containing gland-cells were not observed, and in par- 

 ticular serous cells similar to the parotid cells of mammals do not occur. 

 Intracapsular lymph-nodules occur, and are particularly abundant in 

 the submaxillaries. 



Branchial and Buccal Nerves in Ammocoetes branchialis.f — E. 

 Fusari finds that the branchial nerves give oft' a large number of nerve 

 bundles to the vessels and to all parts of the mucous membrane of the 

 branchial apparatus. Other plexuses give off nerves to the branchial 

 muscles and to the respiratory epithelium. In this last the termination 

 is probably sub-epithelial. In other parts of the apparatus where the 

 epithelium has two or three strata, the termination is intra-epithehal. 

 The sense-bulbs are an exception, for the fibre terminates at the base of 

 the bulb. True sympathetic ganglia were not observed in Ammocoetes, 

 but there are many scattered sympathetic cells, and rich perivascular 

 sympathetic plexuses are not wanting. 



Neuroglia Syncytium in^ Batrachus.J — R. J. Terry describes a 

 neurogha syncytium in the brain of the Teleost, Batrachus tan, where the 

 conditions are unusually favourable for study. The arrangement of the 



* Morpbol. Jahrb., xxxvii. (1907) pp. 10-69 (2 pis. and 16 figs.), 

 t Atti R. Accad. Sci. Torino, xlii. (1907) pp. 493-503 (1 pi.). 

 X Anat. Anzeig., xxxi. (1907) pp. 27-80 (2 figs.). 



