454 



Messrs. Farmer and Moore and Miss Digby. [Mar. 24, 



Furthermore, it is to be observed that whenever this state of things 

 is seen, there is always, so far as we have observed, at least one con- 

 tiguous cell which is destitute of a nucleus (see figs. 1, 2, 4). We 

 convinced ourselves of this highly important fact by examining entire 

 prothallia that had been carefully stained, as there was always the 



Fig. l. 



risk that in erections the appearance might be due to the displace- 

 ment of the missing nucleus. 



We were further able to trace the migration of the nucleus from one 

 cell into that of its neighbour in a sufficient number of instances to 

 convince us that this affords the explanation of the peculiar circum- 

 stances just mentioned (figs. 3, 4). In several instances the nucleus 

 was seen in the act of passing through the wall, and in others the 

 path through which it had traversed was plainly visible as a perfora- 



