AGGREGATION IN THE TENTACLES OP DROSERA. 317 



almost absolutely so ; its disappearance is ascribed by my 

 father^ to the loss of the gvaniiles which ordinarily make its 

 movement perceptible^ and which^ as he believes, are absorbed 

 by the aggregated masses. But although the flowing pro- 

 toplasm may be invisible, evidence of its existence may be 

 found in the free particles which can be seen occasionally 

 travelling round the cell. Moreover a protoplasmic network 

 can sometimes be detected in a strongly aggregated cell after 

 death. In one case an aggregated tentacle was mounted in 

 water and cemented with dammar varnish/ with a view to 

 watching the process of dissolution; this tentacle died before 

 the process began, and Fig. 3 is a drawing of one of its cells. 

 In consequence of death the protoplasmic network became 

 visible, passing, as shown in the figure, from one chlorophyll 

 body to the next, like the processes of connective-tissue- 

 corpuscles, and just as the current does in many living cells 

 (fig. 8). I have also seen the protoplasmic network in speci- 

 mens killed in osmic acid and left in absolute alcohol for a 

 day or two.; they Avere then transferred to glycerine by 

 Strasburger's method of adding a few drops of the latter to 

 a quantity of alcohol, and allowing it to evaporate. In 

 this way I clearly saw cells in which strongly aggregated 

 masses coexisted with a protoplasmic network. These 

 networks are more delicate than the currents seen in the 

 living cell, I suppose owing to the shrinking caused by the 

 alcohol. 



Altogether the impression left on the mind by a study of 

 the protoplasmic currents is that they are not capable of pro- 

 ducing the changes that occur in the aggregated masses. 

 This impression is not one that can be tested, for the question 

 is obviously one of degree ; a sufl[iciently abundant proto- 

 plasmic network containing small aggregated masses in its 

 meshes mitjJbt be able to produce changes in them similar to 

 those, of aggregation. There is another peculiarity of the 

 aggregated masses which seems to shows that they are not 

 passive condensations of cell sap, namely, that they frequently 

 contain large vacuoles apparently filled with colourless, or 

 very slightly tinted, fluid ; a cell in which some of the cells 

 are in this condition is shown in fig. 2. In many instances 

 a single mass contains many vacuoles, giving it a far more 

 complex aspect than that of the simple example of vacuolation 

 here given. But what is of importance is, that in the alterations 



' 'Insectiv. Plants,' p. 48. 



' This otherwise useful varnish does not answer the above purpose, as it 

 almost always runs under the cover glass after a time. Kiihne recommends 

 masiich dissolved in chloroform. 



