236 



Part III. — Fifteenth Annual Report 



difference with regard to place of spawning from the gadoids is therefore 

 an instance, as in the whiting, of the tendency for the eggs to gradually 

 acquire the habitat of the adult. The estuarine habits of the sprat have 

 no doubt been acquired (as in the flounder), and at the present time the 

 sprat only leaves this adult-habitat to as little an extent as is possible 

 commensurate with a pelagic egg. In the case of its near relative, the 

 herring, with a demersal egg, there are no difficulties of pelagic drifts to be 

 overcome, and herrings may (e.g., in the Schlei) lay their eggs in brackish 

 or nearly fresh water, and again, the eggs of the shad appear more as if 

 they were formerly pelagic, but now sink to the bottom in the river. 



Dannevig gives us no data upon the incubatory period of .the sprat's 

 egg, but it is probably more rapid in development, in proportion to its 

 size, than is the case with the gadoids or pleuronectids. 



TABLE VII. — EGGS OF DAB. 



Firth of Forth. 



Feb. 19, 

 Mar. 6, 

 16, 

 19, 

 „ 19, 

 » i 20, 

 „ 20, 

 „ 25, 

 „ 29, 

 „ 29, 

 30, 



April 3, 

 „ 4, 

 „ 4, 

 „ 5, 

 „ 5, 

 „ 5, 



13, 

 14, 

 14, 

 16, 

 16, 

 16, 

 17, 

 17, 

 17, 

 18, 

 18, 

 18, 

 19, 

 19, 

 19, 

 20, 

 21, 

 22, 

 22, 

 23, 

 23, 

 24, 

 25, 

 25, 

 25, 

 26, 

 26, 

 28, 

 2, 



May 



1891. Station VIII., 

 1895. 



1894. Largo Bay., . 

 1891. Station V., 



1895. ,, VIII. and IX., 

 „ v., . . 

 „ v., . . 



1891. ,, VI., . 



1894. ,, V., 

 „ VI., . . 



1891. ,, II., . 

 1893. E. of May Island, . 



1892. 9 miles E. of May Island, 

 „ 10 „ 



,, 8 to 12 miles E. of May Island 

 ,, Cross-section I. (N". half), 



1895. Prestonpans to mid-Forth, 



1892. Cross-section II., 



„ „ HI., • • 



1891. Liston Bank, . 

 Station VIII., 



1893. „ IX., . 



1894. „ I., 



III., . . . 



1892. Cross-section III., . 



„ „ VIII., IX., 

 W. of May Island, . 



1895. Station III., . 



1894. ,, VI., . 



1895. „ II., 



1893. ,, VI., . 

 1895. ,, VII., . 



1892. Cross-section III., . 



„ III. (N. half), 



1893. Station I., 

 1892. ,, II., . 

 1895. ,, IX., . 



„ VII., . . . 



m V 



„ VI., . . . 



1890. „ IX., . 



1892. ,, III., . 



„ IV., . . . 



1893. Cross-section I., 

 ,, Station I., 



„ VI., . . . 

 „ HI-, • • • 

 1892. „ VII., . 



2. 



130. 



Eggs of. 

 3. 

 3. 

 1. 



Egi;s of. 



6. 



77. 



Kggs of. 



39 (early to later). 



117 (early to advanced). 



113 advanced (dab and flounder). 



Considerable numbers. 



Eggs of. 



60. 



A few. 

 A few. 



Many eggs of. 

 A few. 



3 (advanced). 



33. 



1. 



A few (fairly advanced). 



270. 



6. 



71. 



10 (early). 

 383. 



Fair abundance (advanced). 

 26. 



A few. 

 A few. 



34 (dab and flounder). 

 6. 



192. 

 1567. 

 511. 

 268. 

 Eggs of. 



Dab (advanced). 



10 (advanced to later). 



66 (early to later). 



22 (flounder and dab) advanced. 



6. 



Eggs of (advanced to later). 

 7. 



