.Mr. E. W. L. Holt on the Ova o/'Gobiii3. 35 



to 1"2 milliin. Tlic contour is somewhat pyriform and the 

 narrow end (havinG: a diameter from '42 to '48 millim.) is 

 blunt aiul ahnost truncated. The hirger end, on which the 

 e^rg rests, is from "GS to '74 millim. at its ,2:reatest width and 

 tapers rapidly below that point to a small facet or pedicle of 

 attachment. 



As seen in PI. II. fig. 3, the shape of the egg is subject to 

 slight variation. Of the egg-contents it is difficult to speak 

 with certainty, as the treatment received may well have 

 induced some changes. 



In those which appeared to be the best preserved the peri- 

 vitelline space is large and is principally in the lower region 

 of the Q^^. The yolk is bean-shaped, and the embryo, which 

 is somewhat advanced though without free caudal growth, 

 lies in the lone: axis of the eijir. Yolk and embryo too;ether 

 have a long and short diameter of about "Ol and "37 millim. 

 resj)ectively. Both are of course opaque, but it is j)ossible to 

 make out what appear to be very numerous oil-globules of 

 various sizes, occurring all over the yolk and apparently 

 forming the bulk of that structure. 



The zona radiata is very thin, showing under a high power 

 the usual closely-set minute dots or punctures. 



The apparatus for the attachment of the egg is the most 

 remarkable feature. From the facet or ])cdicle of attachment 

 (tig. 1, p) springs a hyaline structure, which spreads outward 

 in the form of an umbrella. Under a high power this struc- 

 ture is seen to be pierced by alternate concentric rows of 

 diamond-shaped or ovoid apertures (tig. \jSp), which increase 

 in size the further they lie from the pedicle, whilst, on the 

 contrary, the proximal interstitial hyaline matter is more 

 massive than that surrounding the more remote rows of 

 apertures. Three or four such rows of apertures can be made 

 out, beyond which the structure is continued in the form of a 

 fringe of long and tapering threads, which adhere to the shell 

 and to the threads of the adjacent ova (fig. \,Jil.). The ova, 

 though very closely packed together (fig. 2), do not adhere 

 to each other or to anything except by means of this tissue. 



From the nature of the apertures the whole structure has 

 the appearance of being composed of a number of threads, 

 radiating from the pedicle and so arranged as to cross each 

 other frequently in the proximal part of their course. But 

 the closest examination under a high power (Zeiss D, Oc. 2) 

 fails to support this appearance. The interstitial matter 

 between the proximal rows of apertures is entirely homo- 

 geneous and cannot be resolved into fibres either in stained 

 or unstained specimens ; but between the larger distal aper- 



3* 



