300 THE COD FAMILY. 



examined the ovaries of two very fine specimens of about 

 15 Ibs. weight, and measuring 34 inches in length. In one of 

 these he found large clear eggs having a diameter of 1/4 to 

 1'32 mm., and he estimated the total number to range from 

 790,000 to more than 2 millions. 



The first ripe eggs were obtained on the 27th April from 

 the Bergen Bank by Mr Mackie, Assistant Fishery-Officer, 

 Peterhead, and by Mr Duthie, holding the same position at 

 Lerwick, from 20 to 40 miles off shore, but they were unferti- 

 lized and had been preserved before reaching the laboratory. 

 Mr Duthie, however, shortly afterwards succeeded in fertilizing 

 a fine series in Shetland and forwarded them alive to the St 

 Andrews Marine Laboratory 1 , where they arrived on the 25th 

 May, or four days after fertilization. The milt is comparatively 

 small, appearing in a male specimen of good size as a frilled 

 riband only 2 to 3 inches in length. 



The eggs are typically pelagic, floating freely in the water, 

 and having a diameter of '0525 inch (T333 mm.), while the large 

 oil-globule measured from '009 to '0105 inch ('228 to '266 mm.). 

 The latter is characterised by its pale reddish-brown hue under 

 a lens, and its faint reddish colour by transmitted light (Plate 

 III, fig. 11), and in some a series of minute fatty granules lie 

 under the large globule. No pelagic egg presents a more 

 distinctive hue, so that it can readily be recognized in any 

 collection. Oil-globules render a pelagic egg more conspicuous, 

 and the colour in this case is a marked feature. The capsule is 

 remarkably tough and resistant, and the fresh egg can only be 

 ruptured by the exercise of considerable force. The punctures 

 of the capsule are unusually distinct, and moreover it is marked 

 by faint lines or creases, so that it resembles that of the brill, 

 lemon-dab and sail-fluke. The micropyle (aperture for fertili- 

 zation) is like that of the haddock, the external opening, which 

 is in the centre of a depression, being smaller than the internal. 



As the eggs had reached the fourth day, the earliest 



stages were not observed. The blastopore was in the act of 



closing or had closed, and the eye-vesicles had formed, while a 



broad wing-like expansion extended along each side of the 



1 W. C. M. Tenth An. Rept. S. F. B. p. 288, PI. XV, 1892. 



