OVARY AND OVARIAN OVA IN CERTAIN MARINE FISHES. 109 



cent., the sections being stained with safranin. The longer 

 diameter of the egg represented is "53 mm. 



My sections from the gurnard do not show any later stages 

 of the egg in which the changes immediately preceding the 

 ripe condition are taking place, namely, the fusion of the yolk 

 globules, and the passage of the nuclear elements to the 

 periphery. I will pass on now, therefore, to the consideration 

 of eggs of similar kind in other species. 



The eggs of the turbot and brill are so similar that they may 

 be described together. They differ from those of the gurnard 

 in three particulars: (1) tlieir smaller size; (2) the greater 

 uniformity of condition among the eggs in a single fish ; (3) 

 the less conspicuous appearance of the oil vacuoles in prepared 

 sections. 



I have prepared sections from a portion of the ovary of a 

 turbot, 1 foot 9^ inches long, which was obtained from 

 Grimsby market on April 12th, 1895. The material was pre- 

 served with picro-sulphuric acid. The condition of the yolked 

 ova in these sections is good, the protoplasmic ova show the 

 contracted condition usually seen in sections from market 

 material. When fresh this ovary was found to contain 

 opaque white eggs advanced in development, but none in the 

 ripe transparent condition. The contrast between the internal 

 and external zone was not visible, the stage of development 

 being too advanced. • 



Figs. 10, 11, 12 represent eggs in three different stages as 

 they appear in these sections. The great majority are in the 

 condition seen in fig. 12, in which the extra-nuclear region is 

 everywhere crowded with round yolk globules, excepting the 

 space occupied by the oil vacuoles near the nucleus. The egg 

 section drawn is '35 mm. in diameter. This is the stage a 

 little before the fusion of the yolk globules commences. A 

 proportion of younger eggs in successive stages are present in 

 the sections. In the stage represented by fig. 11, the large 

 size of the yolk globules is remarkable. This stage in the 

 turbot corresponds with that of fig. 8 in the gurnard, and it 

 will be seen that in the turbot the yolk globules are larger and 



