EMBRYOLOGY OF THE SEA BASS. 
275 
PLATE XCII. 
Surface view of blastoderm ( 17 hours) — germ ring formed all round blastoderm edge. A. 4. 
Surface view of blastoderm (20 lioiirs) — h. e.= Lead end of embryonic anlage. A. 4. 
Side view of embryo (20 hours). A. 4. 
Side view of embryo (25 hours). A. 4. 
Embryo of 25 hours — from above. A. 4. 
Embryo of 31 hours— from the side. A. 4. 
PLATE XCIII. 
Fig. 39. Tail end and blastopore of embryo, 31 hours. A. 4. 
Fig. 40. Antero-posterior section through the jiosterior pole of Fig. 32, m-m' = apical cells of the 
randwulst. F. 4. 
Fig. 41. Antero-posterior section through a blastoderm just a little older than Fig. 32 — to show in- 
growth of germ ring (pr. h.) at embryonic pole. D. 4. 
Fig. 42. Antero-posterior section through a stage such as Fig. 33. A. 4. 
Fig. 43. Longitudinal section through posterior pole of a blastoderm between Figs. 33 and 34. F. 4. 
Fig. 44. Longitudinal section through posterior pole of a blastoderm of 20 hours. F. 4. 
PLATE XCIV. 
Fig. 45. Part of longitudinal section through posterior pole of blastoderm of about same stage as Fig. 
41 — unusual involution of epidermic cells. F. 4. 
Fig. 46. Long section through anterior pole of same stage as Fig. 43. v. mes, extra-embryonic part of 
germ ring (homologous with ventral mesoblast of Amphibia). F. 4. 
Fig. 47. Transverse section through a-h of Fig. 33. 
Fig. 48. Longitudinal section through anterior pole of same blastoderm as Fig. 44. 
Fig. 49. Transverse section through posterior pole of Mackerel blastoderm (27 hours) — intermediate 
between Bass blastoderms given in Figs. 35 and 36. D. 4. 
Fig. 50. Part of transverse section through embryonic shield of Mackerel blastoderm, 27 hours. 
Fig. 51. Section through extra-embryonic germ ring {v. mes.) of Mackerel, 27 hours — blastoderm half 
round yolk. D. 4. 
Fig. 52. Longitudinal section to one side of median line of Mackerel blastoderm, 29 hours. C. 4. 
Fig. 53. Trans, section through anterior part of embryonic shield of Mackerel blastoderm, 30 hours — 
just a little less advanced than Fig. 36. 
Fig. 
33. 
Fig. 
34. 
Fig. 
35. 
Fig. 
36. 
Fig. 
37. 
Fig. 
38. 
PLATE XCV. 
Fig. 54. Transverse section through posterior pole of embryonic shield of Mackerel, 30 hours. (Same 
embryo as Fig. 53.) 
Fig. 55. Median longitudinal section of embryo, 25 hours. C. 4. 
Figs. 56 (one-twelfth immersion), 57 (D. 4), 58 (D. 4). Transverse section through embryo, 25 hours. 
(Letters refer to objectives.) 
Fig. 59. Median longitudinal section through embryo, 29 hours. D. 4. 
Figs. 60, 61, C2. Transverse sections through embryo, 29 hours. D. 4. 
PLATE XCVI. 
Figs. 63, 64 (same series as 60-62). Transverse sections through embryo, 29 hours. D. 4. 
Fig. 65. Median longitudinal section through posterior end of embryo, 33 hours. D. 4. 
Figs. 66 (D) 67 (D), 68 (F), 69 (D), 70 (F). Series of transverse sections through embryo of 35 hours, 
(Letters refer to objectives.) 
