164 F. 0. BOWER. 



striated appearance noted in other objects (fig. 7, a). As time 

 goes on the striae become more plain, and resolve themselves 

 into protoplasmic strings. These were observed to run not 

 only to the lateral walls separating contiguous cells, but also, 

 and apparently in equal numbers, to the free walls of the cells, 

 which are not pitted. As in the prothallus, so here fresh 

 substance is drawn out from the main mass of protoplasm, in 

 this case as thick conical processes (fig. 7, b), which give a 

 very striking appearance to the whole protoplasmic body about 

 two hours after plasmolysis. The observations made in the 

 prothallus as to apparent branching of strings were confirmed 

 in the behaviour of the strings of protoplasm in these cells. 



It being possible after their thickening to trace the indi- 

 vidual strings, it could be seen whether they run as a rule or 

 chiefly to the pits, or whether there is any constant relation 

 between them and the pits. On examining a large number of 

 cases I have found that strings of protoplasm often do run to 

 pits, and that strings from the contracted protoplasm of con- 

 tiguous cells are often opposite to one another ; but that a 

 much larger proportion of the strings are not opposite to one 

 another, and run to points on the cell wall where there are no 

 pits. In other words, I conclude that in Trichomanes 

 pyxidiferum my observations on plasmolysis give no clue 

 to there being any special relation of the protoplasm to the 

 pits. This is, however, no proof that some special relation 

 does not exist. 



Concluding Remarks. 



From the above observations it is seen that the connection 

 between the protoplasm and the cell wall, as shown by plas- 

 molysis in those cases which have been observed, is closer 

 than is usually described, or at least implied in current 

 botanical writings. The objects were selected from very dif- 

 ferent systematic groups ; it is true their number is small, and 

 it must be admitted that the effect is not visibly produced in 

 every cell ; nevertheless, though it cannot be asserted that the 



