OVARY AND INTRA-OVARIAN EGG IN TELEOSTEANS. 303 



is well known that in many Teleosteans all the eggs are not shed at 

 once, but are rather got rid of a few at a time, brief intervals 

 occurring between each extrusion. In sections of spent ovaries the 

 first thing which strikes one is that the remaining great ova are in 

 many cases provided with a complete nucleus with its surrounding 

 membrane, and nucleoli arranged round the periphery, just as is 

 seen in the egg before it is ripe.* 



The majority of the ova, however, either show the after condition 

 in which the nuclear membrane has vanished and the nucleoli are 

 collected towards the centre, or they are in the condition of having 

 no nuclei at all, and are advanced in the process of disintegration. 

 When in this last condition they present a vacuoled and atrophied 

 appearance, seen in fig. 4, where an ovum with nucleoli still present, 

 although the outer protoplasm of the egg is beginning to show signs 

 of decay, is also seen. The eggs still presenting the nucleated 

 appearance are a few which, in my estimation, have never become 

 quite ripe ; and, from the appearance of the ovary before spawning 

 takes place, I am inclined to think that a few must be extruded in 

 this condition. One does, in fact, generally notice that when ferti- 

 lizing by artificial means a quantity of spawn, there are some which 

 seem impervious to the action of the spermatozoa. 



The eggs left in the spent ovary become opaque, and can readily 

 be noticed in the fresh organ on this account. They are present 

 for a considerable time after spawning is over. 



The small nucleoli, budded off in the manner already mentioned, 

 eventually appear to become free in the loose debris of the spent 

 organ by the total disintegration of the protoplasm around them. 

 The progressive history of the nucleoli can be seen very well in 

 the conger, because these bodies are of specially large size. In 

 studying this form the usual appearance is seen to be granular, but 

 in some instances the granules are arranged in the form of a circle 

 placed eccentrically, as seen in fig. 5. As the egg approaches 

 ripeness, however, I find some interesting appearances. While the 

 nucleus has yet a distinct membrane, and the nucleoli are oval in 

 outline — the long axis being placed in a radial manner — a clear 

 highly refracting band appears across the short axis. This band 

 becomes spherical, and increases in size till the granular substance 

 of the nucleoli is collected only at the two poles. I notice, how- 

 ever, that the inner pole has always more granular matter than the 

 outer. These vesicular bodies have a distinct double contour, and 

 are of a somewhat smoky colour even in stained sections. Their 

 growth is towards the nuclear membrane, and eventually, when this 



* III one iustance I observed that a large nucleolus was about to give off four small 

 circular nucleoli, showing that the progressive development had not yet ceased. 

 NEW SERIES. VOL. 11, NO. IV. 24 



