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BOTANICAL GAZETTE 



[FEBRUARY 



the intersporic nucleus which may be worth recording. The nucleus 

 enlarges greatly as development proceeds, retains its position at the tip 

 of the spore cavity, and at the time of fertilization is vastly larger than 



fis 



In this figure 



the peculiar shape of the nucleus attracts attention. Two long arms 

 are projecting towards the prothallium, and other filaments extend 

 upward from one side. The shape of the nucleus is not at all constant, 

 but at this stage it is generally furnished with fine extensions radiat- 

 ing towards the prothallium. Fig. 4 shows the nucleus of another 

 spore at the same stage. As development proceeds, the nucleus frag- 





Fig. 4. 



Fig. 5. 



Fig. 6. 



Fig, 4. — The same as^^. j, showing nucleus of spore cavity. X 1050. 



Fig. 5. — The same asyf^. 5, showing papilla of spore cavity with two fragments 

 of the nucleus {fsn) ; later stage than above. X 370. 



Fig. 6.— rThe same ^.^fig^s^ showing fragmentation carried still further. X 1050. 



raents amitotically into a number of parts. Pig^5 represents two such 

 fragments, one on each side, after the embryo has begun to develop. 



/. 



The reticulum is 



throughout very dense and homogeneous and a nucleolus is present. 

 It is hardly probable that the peculiar processes figured can be an 

 artifact, as all other parts seem very well fixed. If these processes are 

 normal, as seems probable, they recall the filaments extending from 

 the nucleus into the food mass in the egg cell of Dytiscus (Wilson, 

 The Cell, p. 115). In the case of Marsilia, however, the processes 

 extend towards the tissue to be nourished, instead of towards the food 

 material. The nucleus is here, doubtless, quite active in the elabora- 

 tion or transference of food material, and it is not surprising that it 

 should show special modification to this end. The final fragmentation 

 reminds one of similar behavior of the nuclei in purely vegetable cells 

 of Chara, Tradescantia, and many other plants, — W. C Coker, 

 University of North Carolina, Chapel Hill. 



