On tlie Life-History of the Shanuy (Blennius pholis L.). 371 



numerous larger oil-globules are formed by the coalescence of tbe 

 smaller. 



The disc (d) attached to one pole of the egg is circular and, 

 wheu fresh, of a pale pinkish hue, and it is generally slightly larger 

 than the long diameter of the egg. Many of the discs have a fin- 

 ished appearance, as might be anticipated, since they are the product 

 of the ovarian foUicles. In others, however, the edge is spongy — 

 with projecting processes. In minute structure the whole is granulär, 

 and no special differentiation of the tissue takes place as in the 

 gobies — where the disc of attachment is finely reticulated. 



Dr. R. ScHARFF in 1866 i clearly indicated the pecnliarly modified 

 follicle in the ovary of the shanny. He observes »The depth of the 

 cells, which in one half of the egg is only about 0.007 mm gradually 

 increases until it reaches 0.032 mm at the opposite side. The cells 

 at that side become drawn out and taper towards the surface of the egg. 

 The Space between the cells is filled with interstitial substance. Another 

 feature about the follicle in this case is that it touches the zona in 

 all parts except in a circular portion where it is not in immediate 

 contact with it. This space is filled with an apparently viscid sub- 

 stance, which is no doubt secreted by the follicullar cells.« He men- 

 tions that Eimer, Brock and McLeod have observed similar modi- 

 fications of the follicle. In all probability such is characteristic of 

 those fishes which have an adhesive disc for the attachment of the 

 egg. This special cellular development of the follicle is observed 

 very early in the growth of the ova and it becomes more and more 

 distinct as they enlarge. At the moment of extrusion it probably 

 secretes the viscid amorphons adhesive disc so importaut for the 

 attachment of the eggs of the shanny to foreign surfaces. 



Unfortunately artificial impregnation of the eggs of the shanny 

 has hitherto failed at Sr. Andrews, though so successful in other 

 fishes, and also in various Invertebrates, and thus the development 

 of the egg and the nature of the larval and post-larval shannies 

 cannot at present be given. Indeed it is noteworthy that during 

 all these years of inquiry at St. Andrews no larval or post-larval 

 shanny has been seen. They have never been captured in the pools, 

 and have not been met with in the tow-nets or bottom-nets in the 

 bay. They therefore in all probability, either lurk amongst the roots 



1 Proceed. Roy. Soc. Vol. XLI. p. 449 and Q. J. Microsc. Sc. Aug. 1887. 

 p. 19 fsep. copy). Plate V. fig. 15. 



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