“In the stages intervening between plate iii, fig. 19, and plate iii, fig. 30, the young Lepidosteus frequently swim about, and become readily separated from their point of attachment. In the stage of plate iii, fig. 30, they remain often perfectly quiet close to the surface of the water; but, when disturbed, move very rapidly about through the water.... The young already have also the peculiar habit of the adult of coming to the surface to swallow air. When they go through the process under water of discharging air again they open their jaws wide, and spread their gill-covers, and swallow as if they were choking, making violent efforts, until a minute bubble of air has become liberated, when they remain quiet again. The resemblance to a Sturgeon in the general appearance of this stage of the young Lepidosteus is quite marked.”
[499] The numbers refer to the list of memoirs of the anatomy and development given at the end of this memoir.
[500] We have examined the structure of the ovarian ova in order to throw light on the nature of these peculiar pyriform bodies. Unfortunately, the ovaries of our adult examples of Lepidosteus were so badly preserved, that we could not ascertain anything on this subject. The ripe ova in the ovary have an investment of pyriform bodies similar to those of the just laid ova. With reference to the structure of the ovarian ova we may state that the germinal vesicles are provided with numerous nucleoli arranged in close proximity with the membrane of the vesicle.
[501] “Ueb. d. Entwick. d. Central Nerven Systems d. Teleostier,” Archiv für mikr. Anat. Vol. XV. 1878.
[502] Salensky, “Recherches s. le Développement du Sterlet.” Archives de Biol. Vol. II. 1881, pl. XVII. fig. 27.
[503] “Beiträge zur Entwick. d. Knochenfische,” Zeit. f. wiss. Zool. Vol. XXIII. 1873, taf. III. fig. IX. 2.
[504] Journal of Anat. and Physiol. Vol. XI. p. 491, plates XX. and XXI.
[505] “Elasmobranch Fishes,” p. 156, plates 10 and 13. [This edition, p. [378], pl. 11, 14.]
[506] “Elasmobranch Fishes,” p. 136, plate 11, fig. 10. [This edition, p. [354], pl. 12.]
[507] F. M. Balfour, “Monograph on the Development of Elasmobranch Fishes,” p. 87, plate 9, fig. 2. [This edition, p. [303], pl. 10.]