JOURNAL OF MICROSCOPICAL SCIENCE. 



DESCRIPTION OF PLATES XVI, XYII, XVIII 

 & XIX. 



Illustrating Mr. Isao lijiraa^s Paper " On the Origin and 

 Growth of the Eggs and Egg-striugs in Nephelis, with 

 some Observations on the ' Spiral Asters.' '^ 



5—7 ff., 5th — 7th ganglion, a. Rachal line. B. Mediad line. cir. 

 Circular muscle-fibres, ex. External layer of the ovary-wall. /. o. Female 

 orifice, fol. follicle, t/. c. Germ-cells, ger. Germogen. g. v. Germinal 

 vesicle. I. ep. Lining epithelium. long. Longitudinal muscle-fibres. 

 m. 0. Male orifice, m. s. Mediad side. 7i. Nucleus of the cellular tissue 

 investing the ovaries, ov. Ova. ova. Ovary, ra. Rachis. ra. s, Rachal 

 side. s. cir. Semi-circular muscle-fibres, sp. Spermatozoa. st Egg- 

 strings. (. Testis, t. ov. Termination of ovaries, v. d.^. Beginning of 

 vasa deferentia. v. d.n. Coiled portion of ditto, v. d.^. That portion of 

 ditto lying beneath the testicular sacs. v./. Vaso-fibrous tissue, y.fol. 

 Young follicle, y. n. Yolk-nucleus. 



PLATE XVI. 

 Fig. 1. — The reproductive organ in situ, magnified about three times. 



Fig. 2. — The right ovarial tube drawn half-diagrammatically, showing 

 the germogen and the egg-strings. Magnified about ten times. 



Fig. 3. — A surface view of the ovary-wall, made out from both chromic 

 acid and picro-sulphuric acid preparations. ( x 450.) 



PLATE XVII. 



Fig. 4.— a cross-section of the ovary-wall, on the rachal side, showing 

 different stages of the germogen. Picro-sulphuric acid, (x 450.) 



Fig. 5. — A cross -section of the germogen, a little more advanced in 

 development than that of Fig. 4. Picro-sulphuric acid. ( x 450.) 



Fig. 6. — A longitudinal section of an egg-string, somewhat schematically 

 drawn. Magnified about twenty-five times. 



Fig, 7. — A cross-section of an egg-string, in the plane of a — a of Fig. 6. 

 Chromic acid, (x 165.) 



Fig. 8.— a cross-section of the same in the plane of B— n of Fig. 6. 

 Chromic acid, (x 165.) 



Fig. 9. — A cross-section of the same at about c— c of Fig. C. Chromic 

 acid. (X 165.) 



Fig. 10. — The cross-section of the same at about D— d of Fig. 6. 

 Chromic acid. (165.) 



