150 J. T. CUNN1NC4HAM. 



of homogeneous compact spheres of clifFereut sizes (1 to 5 fi) 

 and numbers (20 to 100). The membrane of the nucleus in 

 this stage disappears, and the chromatin masses wander apart, 

 forming the smallest nuclei lying free in the plasma. These 

 dense homogeneous nuclei send out processes and embrace 

 vacuoles of the plasma, until they contain several of these, and 

 then they again assume a smooth outline. The nuclei in this 

 stage have thus a membrane of chromatin and a framework of 

 partitions between the vacuoles which appears optically as a 

 reticulum. This process recalls the vacuolation of nucleoli 

 seen in the germinal vesicle of Teleostean and Amphibian eggs, 

 and also the vacuolation of the chromosomes described in 

 the reconstitution of nuclei after mitosis in segmenting ova. 

 The chromatin is seen in granules in the network, and it accu- 

 mulates into a single mass in the centre, or fixed to one side 

 of the membrane. From the mass extend linin threads; then 

 the mass of chromatin breaks up, granules passing in suc- 

 cession along the threads to the points where these join the 

 membrane, and there forming the spherical masses ; the 

 achromatic threads then break or dissolve, and so we have the 

 recurrence of the condition from which we started, and the 

 process begins over again. All this suggests strongly that 

 the multiplication of nucleoli in the Teleostean ovum, and 

 their disappearance at a later stage, are effected by the stream- 

 ing of chromatin along threads of linin. 



The Mursenidse. 



In consequence of the peculiarities in their reproduction 

 the generative organs of the conger and eel will be here 

 considered separately. For a fuller discussion of their 

 natural history I must refer to my papers in the ' Journal of 

 the Marine Biological Association,^ and the literature to which 

 references are there given. It is sufficient to mention here 

 that they do not spawn annually, nor periodically, but only 

 once, after which they die, and that their adolescent or imma- 

 ture stage extends over several vears. 



