228 



bulletin: museum of comparative zoology. 



EXPLANATION OF PLATES. 



All figures are from preparations of cliick embryos except when otherwise stated. 

 All, with the exception of the photomicrographs and diagrams, were drawn with 

 the aid of the camera lucida. The magnifications follow the descriptions of the 



figures. 



Abbreviations. 



'.'/■ 



Gn 



d. . . 



d: . . 



cl." . . 

 d. com.it. 

 d. co in. t.' 

 d. comit.' 

 d.gn. . 

 d. gn. cil. 

 cl. med. in 

 ec 1 drm. 

 gn. cil. . 

 gn. cU> 

 gn. Gas. 

 gn. mx-m 

 gn. t'i. 

 1/6.. . 

 1. . . 

 m. . . 

 tub. lint, ex 

 nts'e. . 

 ms'ench. 

 mt'e. . 

 mu. ob. d 

 mil. ob. o 

 mu. rt. a. 

 mu. rt. d. 

 mu. rt. p. 

 mu. rt. v. 

 mil. rt. v. -f «. 

 n. dbd. 

 ■n. cil. oc'mot. 

 n. cil. trig. 

 n. oc'mot. . 



Itvlifferent cell. 



Indifferent cell. (See explanation of Fig. 16.) 



Indifferent cell. (See explanation of Fig. 10.) 



" Accompanying " cell. 



" Accompanying" cell. 



" Accompanying " cell. 



Ganglion cell. 



Ganglion cell of ciliary ganglion. 



Migrant medullary cell. 



Ectoderm. 



Ciliary ganglion. (See explanation of Fig. 17.) 



Erroneously engraved for gn. cil. (Fig. 2). 



Gasserian ganglion. 



Ma.xillo-mandibular portion of Gasserian ganglion. 



Transitory ganglion. 



Infundibulum. 



Lateral. 



Median. 



External limiting membrane. 



Midbrain. 



Mesenchyme. 



Hind-brain. 



Dorsal oblique muscle. 



Ventral oblique muscle. 



Anterior rectus muscle. 



Dorsal rectus muscle. 



Posterior rectus muscle. 



Ventral rectus muscle. 



Ventral and anterior rectus muscle9. 



Abducent nerve. 



Oculomotor ciliary nerve. 



Trigeminal ciliary nerve. 



Oculomotor nerve. 



