M alt i nucleated Condition of tht Veydahk Cell. 45 



Acanthus mollis (Plate V. figs. G and 7). 



In this plant the multinucleated condition is well seen 

 in the ground tissue. More remarkable, however, than 

 the occurrence of more than one nucleus in some of the 

 cells, is the fact that most of the nuclei contain several 

 nucleoli, and these in tarn may contain several endo- 

 nucleoli. The nuclear membrane was most distinct, and 

 in one specimen the nucleolar membrane could be plainly 

 seen. 



The nuclei sometimes exhibited an indistinct, irregular 

 outline, and had the appearance of being about to disin- 

 tegrate. The tissues examined w^crc those of the petiole, 

 and the plant was past maturity. 



As in Polygonum Sieboldii^ the nucleoplasm was dense 

 and finely granular ; but the most noticeable fact in con- 

 nection with this subject was, that there was sometimes 

 a hyaline layer of protoplasm in the nucleus, in which 

 was placed the nucleolus. This, I fancy, seemed to occar 

 oftenest in large, well-nourished looking nuclei (PI. V. fig. 

 la). In sucli a case as this one cannot fail to see that 

 the nucleolus is a most distinct body, and does not at all 

 resemble a " thickening of the intranuclear network," or 

 the " result of a shrivelling up and intimate fusion of a 

 part of the network." It is worthy of notice that in the 

 cells of this plant, or indeed other plants, where the 

 nucleus contains several nucleoli, there is usually one 

 nucleolus larger than the rest, and which contains several 

 endo-nucleoli instead of one (PI. V. fig. 7c?). 



Various stages of direct division have been observed in 

 this plant. One case (PI. V. fig. 6) was especially inter- 

 esting, and served to illustrate the fact that the imcleolus 

 always takes precedence of the nucleus in division. The 

 nucleus had become constricted at one side ; the nucle- 

 olus, however, was also constricted, and bent down over 

 the nuclear constriction, so that it must have been divided 

 before division of the nucleus could take place. 



Eschscholtzia californica (Plate V. fig. 8). 



In longitudinal sections of the stem of this plant the 

 multinucleated condition was chiefly found in the ground 



