156 F. 0. BOWER. 



often little or uo visible connection remaining between it and 

 the cell wall. Frequently, however, there is to be seen from 

 the first a faint silky striation in the space between the proto- 

 plasmic body and the cell wall, running in a radiating manner 

 between them. This is in most cases extremely delicate, and 

 even with Zeiss, obj. F, it is sometimes impossible to define the 

 appearance as any distinct system of lines. Again, in other 

 instances coarser threads, the outlines of which can readily be 

 made out with high powers, are seen from the first to maintain 

 a connection between the cell wall and the contracted proto- 

 plasm. On these coarser threads are often to be seen nodal 

 thickenings, similar to those described by Gardiner. Though 

 the above difference is easily recognised under the microscope, 

 there can be little doubt that the appearances are merely 

 phases of one and the same phenomenon. 



In those cases where there is at first no visible trace of a 

 connection between the protoplasm and the cell- wall, there 

 usually appears, after the lapse of a short time, a striation of 

 the intervening space similar to that which may often be 

 observed from the first ; while in the latter case the striation 

 becomes more obvious, and after a short time (e. g. quarter or 

 half an hour) it may be seen that it is due to the existence of 

 numerous very delicate threads, which extend from the proto- 

 plasmic body to the cell wall. Some idea of the fineness of 

 these threads in the first instance may be gained from the fact 

 that they cannot be individually defined even with high power 

 (F., Zeiss). Fig. 1 represents cells as they appear about a 

 quarter of an hour after plasmolysis -^ the threads, being tense 

 at first, appear quite straight. Some time after plasmolysis 

 has taken place, and the strings have become more obvious, 

 they may be seen to be executing rapid and more or less irre- 

 gular vibratory movements; these show that they are not then 

 very tightly stretched. The strings run not only to those 

 walls which separate contiguous cells, but also to the free 

 marginal walls as represented in the figure, and further, as 

 may be ascertained by careful focussing, to the walls which 

 ' Compare Priiigsheini'b fiy. IG, Taf. iiij 1. c. 



