1900] THE CELL PLATE IN HIGHER PLANTS 163 
lying in the cytoplasm, with some of the original fibers still 
attached to it while the daughter nuclei were again dividing. 
Whether this cell plate and wall were finally completed, I did 
not determine. The same stage of development of the cell plate 
was often observed, in which no cell wall could be detected. 
The significance of the presence of a cell wall without the pre- 
vious appearance of the carbohydrate material has already been 
discussed, 
The evidence for the splitting of the cell plate before the 
formation of the new cell wall need not be discussed in detail 
here. Treub, in his experiments upon living cells, showed that 
the splitting occurs, and the new wall is laid down between the 
separated halves before the cell plate has attained its full growth. 
My own observations confirm this fact (figs. 79, 37). But one 
83 t of difference should be noted between Treub’s obser- 
“ations and mine. In Treub’s figures the beginning of the 
Process is represented on one side of the cell where the cell plate 
~ reached the membrane of the mother cell, while in my prep- 
eee it may’ be clearly seen that the splitting begins in the 
mrs region of the plate and extends toward the periphery. 
ne mechanics of such splitting is hard to explain. The fact 
had s evidence of it was found except where the spindle fibers 
i ‘appeared would indicate that the fibers have no part in 
Process. From his observations on Fucus, where the 
— which form the cell plate divide before fusion, Stras- 
Riss Songs that the splitting may be the result of a similar 
may ees the higher plants, 7. ¢., the separate cell plate elements 
two ie ; — they fuse. If such a division takes place the 
aos * Temain so close together that no evidence of it 
are so. hice much later stage. Where the cell plate elements 
expect eae as they are in the larch, it is reasonable to 
he lack of nd stages showing their division if it really oreurs 
comes late Such stages seems to me to indicate that the division 
Plate, ¢ nie the elements have fused into a continuous 
“ontinuous is be true, the problem is that of the splitting of a 
Protoplasmic membrane. Strasburger decided that 
