160 J. T. CUNNINGHAM. 



(15) HuBBAKD, Jessb W. — " The Yoke-iiucleus in Cymatogast^r aggre- 



gatus, Gibbons," 'Proc. Amer. Pliilos. Soc.,' vol. xxxiii, 1894. 



(16) Mead,A.D. — " Maturation and Fecundation in Chset opt erus perga- 



mentaceus, Cuvier," ' Journ. of Morphology,' vol. x, 1895. 



(17) KoRSCHELT, E. — "Eireifung und Befruchtung bei Ophryotrocha 



puerilis," 'Zeits. f. wiss. Zool./ Bd. Ix, 1895. 



(18) ScHAUDiNN, Ebitz. — " UntersuchuDgen an Foraminiferen : I. Cal- 



cituba polymorpha, Robaz," 'Zeits. f. wiss. Zoo!.,' Bd. lix, 1895, 



(19) Wilson and Matthews. — " Maturation, Fertilisation, and Polarity in 



the Echinoderm Egg," ' Journ. of Morphology,' x, 1895. 



(20) Cunningham, J. T. — "The Development of the Egg in Flat flshes 



and Pipe fishes," * Journ. Mar. Biol. Ass.,' vol. iii. No. 4, 1895. 



(21) SoBOTTA, J.— ' Anat. Anz.,' 1895. 



(22) Henneguy, L. F. — ' Legons sur la Cellule,' Paris, 1896. 



DESCRIPTION OF PLATES 2—4>, 



Illustrating Mr. J. T. Cunningham's paper, " On the Histology 

 of the Ovary and of the Ovarian Ova in certain Marine 

 Fishes." 



PLATE 2. 



Figs. 1 — 5. — Ovarian eggs of Trigla gurnardus in various stages of 

 growth and yolk formation, as seen in fresh condition with Zeiss's obj. A, 

 oc. 3. From a specimen examined April 26th, 1895, at Grimsby. 



1. Transparent ovum with scattered small globules, probably oily. 



2. Large ovum with internal darker zone of oil-globules, external more 



transparent zone, containing yolk. 



3. Later stage, in which the contrast between the yolk layer and the 



oil-layer is at its greatest. 



4. Later stage, in which the yolk layer has become so opaque as to 



couceal the oil layer. 



5. Stage in which the ovum is approaching maturity, and begins to 



grow transparent again. 



Fig. 6. — Portion of ovary of immature brill, 12f inches long ; examined in 

 fresh condition May 30th, 1895, at Grimsby. Zeiss A, oc. 3. 



Fig. 7. — Ovum of Trigla gurnardus, "28 mm. in diameter. From roe 

 containing some ripe eggs, obtained in the market, fixed with picro-sulphuric 



