April 1892.] THE BOTANICAL SOCIETY OF EDINBURGH. 385 



area, the central endonucleolus, and a great number of 

 minute oval unstained points close to its periphery, the 

 peripheral endonucleoli. A similar appearance is shown by 

 the nucleolus of the primary endosperm-nucleus, fig. 31. 



In fig. 44^ representing the primary endosperm-nucleus 

 some time after its formation, a large nucleolus is seen with 

 a number of minute structures, which have been diagramati- 

 cally represented in fig. 44^ namely : — 



1. A thin unstained nucleolar membrane. 



2. A great number of peripheral endonucleoli. 



3. A deeply-stained, apparently structureless, layer. 



4. A corona of minute, slightly elongated, endonucleoli 



surrounding. 



5. A large central endonucleolus. 



Fig. 43^ 43^. The nucleolus has been represented amplified 

 in 43^ and is made up of : — 



1. An unstained nucleolar membrane {nl. m.). 



2. A not very deeply-stained submembranous area 



traversed by radiating filaments {r. /.). 



3. A very deeply-stained portion, with four compara- 



tively large endonucleoli at its central border (x). 



4. A large number of small radially-elongated endo- 



nucleoli (the proximal ones). 



5. A large central endonucleolus surrounded by an 



annular outbulging or fold (fold). 



rigs. 41 and 42 are very similar to fig. 43, for in fig, 41 

 we find a large central endonucleolus with a highly refractive 

 plate-like body (plate), surrounded by seven small endo- 

 nucleoli of varying diameter. The nucleolus being rather 

 deeply stained further details could not be made out. Fig. 

 42 shows again the large central endonucleolus (4-) sur- 

 rounded by a number of minute endonucleoli smaller and 

 less numerous than those in fig. 43. The body (o) corre- 

 sponds to one of the endonucleoli marked (x) in fig. 43. A 

 nucleolar membrane could again be made out, but nothing 

 further. 



The stages, figs. 41 to 44, are very near one another, but 

 any connection between them and the figures preceding them 

 I have not been able to make out as vet, and I shall trace 



