172 



Papevfi from the Department of Marine Biology. 



VI. Electroplaxes. — Continued. 



Fig. 3. Adult. Longitudinal section of portion of clectroplax. Dorsal vacuoles 



have entu-ely disajipeared. Striations broken and curved. 



Ch. R Chromatic io<l. C Connective tissue. 



Ne Nerve-fiber. C. V Vacuole in connective tis.sue. 



B Blood-vessel. 



VII. Photomicrographs. 



Fig. 1. 20 mm. embryo, X80. Electric area to show relation of electric to mus- 

 cle tissue. 



R. Ex Rectus externus muscle. R. Inf Rectus inferior muscle 



R. Su Rectus superior muscle. A Artery. 



Fig. 2. 33 mm. embryo, X3.). Electric area to show four separate electric organs 



in position. 

 Fig. 3. 80 mm. embryo, X35. Portion of electric area. Fibers of rectus 



superior muscle separated by electric nerve. Overlapping of electroplaxes 



shown. 

 Fig. 4. 33 mm. embryo, X8o. Electric nerve passing through rectus superior 



muscle. Oculomotor ner\-e. Three branches of oculomotor to right. 

 Fig. o. 45 mm. embrj^o, X8.5. Electric and oculomotor branches of III nerve, 



immediately after leaving brain. GangUon of V nerve below. 

 Fig. 6. 45 mm. embryo, X85. Electric and oculomotor branches of III nerve 



passing tlu'ough the foramen in the cranial wall. 

 Fig. 7. 45 m.m. embryo, X85. Electric nerve in rectus superior muscle. Branches 



of oculomotor to right of muscle. 

 Fig. 8. 45 mm. embryo, X85. Large branch of electric ner\'e entering electric 



organ. Oculomotor to right. 

 Fig. 9. 45 mm. embryo, X85. ^^iew from opposite side of embrj^o. Fibers of 



rectus superior muscle entirelj' separated by electric nerve. Nerve breaking 



up in muscle to form branches. Oculomotor to left. 

 Fig. 10. 45 mm. embrj'o, X85. Branches of electric nerve after leaving rectus 



superior niuscle, going to various parts of the electric organ. Branches of 



oculomotor separating to go to muscles. 

 Fig. n. 80 mm. embrj-o, X85. Fibers of rectus superior muscle almost oblit- 

 erated bv the electric nerve. 



