REPORT ON THE SPAWNING OF THE COMMON SOLE. 9 



I bring this forward essentially as a negative conclusion ; as evidence, 

 I mean, that in this form, at least, the axis of symmetry does not 

 always coincide with the first cleavage plane, or always with the second, 

 as some have suggested. When I speak of " coincidence," I, of course, 

 merely mean that the directions of the planes appear to coincide. To 

 be on the safe side, I will only assert that the planes said to coincide 

 were not more than 15° apart, though I believe that in the case of some 

 eggs it is possible to' reduce this angle. 



//. — The axial part of the embryo is formed hy concrescence of the 

 embryonic ring, or lip of gastrula mouth, from in front bachivards. 



