394 JAMES ROLLIN SLONAKER 



Thp distribution of the nerves to the orbit may be briefly sum- 

 marized as follows: 



The oculomotor nerve supplies the superior rectus, the^ infer- 

 ior rectus, the internal rectus, the inferior oblique, and the pal- 

 pebral muscles, and Harder' s gland. Through the ciliary ganglion 

 and short ciliary nerves it supplies the chorioid and possibly 

 some of the long ciliary nerves to the ciliary muscles and the 

 muscles of the iris. It gives rise to at least seven of the short 

 ciliary nerves. 



The trochlearis goes to the superior oblique muscle. 



The abducens supplies the external rectus, the quadratus, and 

 the pyramidalis muscles. 



The ophthalmic branch of the trigeminus sends a branch 

 which unites with a nerve from the ciliary ganglion from which 

 are formed the two long ciliary nerves and one short ciliary 

 nerve. 



The superior maxillary branch of the trigeminus innervates 

 the lacrimal gland, the conjunctiva, the lids, and adjacent parts. 



THE LENS 



The lens of the sparrow differs in many respects from that of 

 man. It is composed of a firm central part, almost spherical in 

 shape, and a less firm peripheral portion (fig. 28, Lns, plate 5). 

 The central portion forms the main bulk of the lens and is the 

 part which functions in sight. 



This central part is completely surrounded by a ring-like 

 pad which forms the periphery of the equator of the lens adja- 

 cent to the ciliary processes. This structure is described by 

 Rabl ('98) and Ritter ('00) as the 'Ringwulst.' I have called 

 it the annular pad (fig. 28, Ap, plate 5). In a preserved lens it 

 is easily separated from the hard, central, spherical part. In 

 fact, in making sections through the whole eye, it is often diflfi- 

 cult to keep the firm center from dropping out of the section. 

 When these two parts of the lens are separated, the center 

 resembles a hard, bullet-like mass and the annular pad a wedding 

 ring. 



