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U. S. BUREAU OF FISHERIES 



St-V-a 



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Fig 2.— Egg and larval stages of the shad (Alosa sapidissima) 



A. Freshly extruded egg enlarged, showing its envelope much wrinkled. 



B. Shad egg, showing vitelliis and distended egg membrane, natural size. 



C. Shows the gradual accumulation of germinal matter at one pole of egg, the polar prominence 



externally, and presence of plasmic processes extending down through the vitellus. 



D. Embryo shad in its natural positiou in its spacious enveloping membrane. Froui a photograph. 



E. Diagrammatic representation of an embryo to show course of segmental ducts «d and extension out- 



ward of pectoral plates pp, which are intimately concerned in tlie development of pectoral fins. 



F. Side view of a young shad 13 days old, viewed as a transparent object, ab, rudimentary air bladder; 



L, liver; Qb, gall bladder. u ^ u 



Q. An embryo in its envelope, on the third day of development, nearly ready to hatcn. 



