. Introduction to zoology; a guide to the study of animals, for the use of secondary schools;. FIG. 111. — An early stage of develop-ment of egg. Appendages becom-ing bifid. Paired dotted areasabove indicate eyes; these are fol-lowed by the first three paired ap-pendages : aiitennules, antennae,and mandibles. Below in the mid-dle line is the forming tail; aboveis the mouth. FIG. 112. - - Surface view of eggnauphius. Antennae show begin-ning of segmentation; mandiblesand maxillae seen on each side ofthe abdomen. Embryo 10-18 daysold. X 25. From Herrick. female now moults, 1mt doe
. Introduction to zoology; a guide to the study of animals, for the use of secondary schools;. FIG. 111. — An early stage of develop-ment of egg. Appendages becom-ing bifid. Paired dotted areasabove indicate eyes; these are fol-lowed by the first three paired ap-pendages : aiitennules, antennae,and mandibles. Below in the mid-dle line is the forming tail; aboveis the mouth. FIG. 112. - - Surface view of eggnauphius. Antennae show begin-ning of segmentation; mandiblesand maxillae seen on each side ofthe abdomen. Embryo 10-18 daysold. X 25. From Herrick. female now moults, 1mt does not spawn again for a wholeyear ; that is, she spawns in alternate years. The numberof eggs carried varies with the age of the female; middle-aged lobsters may carry up to one hundred thousand eggs,but the old or young ones as few as three thousand. Theegg as freshly laid is about millimetres in diameter andis stored with food material, called yolk, much as in thecase of the hens egg. As in the chick, the development 116 ZOOLOGY takes place, as it were, on top of the egg (Figs. Ill, 112).Eyes and mouth appendages early make their appearance;then the other appendages, and the tail (Fig. 113). Fora long time the back of the thorax is greatly distended bythe yolk stored there, and the eyes are huge (Fig. 114). Immediately after hatching, the young lobster is aboutone-third of a
Size: 1435px × 1742px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1900
