44 FREAKS OF PLANT LIFE. 



tint, now holds a clear and colourless fluid, in which 

 floats an elongated dark-coloured body, formed by 

 the aggregation of the colouring matter. This 

 aggregated body, sometimes of a single mass, some- 

 times of two, is constantly changing its form, slowly 

 but gradually, like that curious little animal found in 

 stagnant waters called an Amoeba. Finally, the 

 movement ceases, the masses again dissolve, and 

 become diffused through the contents of the cell, 

 which again assume a uniform tint and appearance. 

 In this cycle we have a manifestation of a great 

 molecular change which is wrought within the cells 

 of the tentacles, in response to some external irritation. 

 Whatever causes the tentacle to become inflected 

 seems also sufficient to induce this phenomenon of 

 the aggregation of masses within the cells. When 

 the influence of that irritation has passed away, and 

 the tentacle has assumed its original erect position, 

 the contents of the cells assume also their homo- 

 geneity, or uniform density. 



This aggregation commences in a tentacle at the 

 upper end, in immediate proximity to the gland, and 

 proceeds from above downwards. It accompanies 

 the bending over of the tentacle, but that it neither 

 causes the inflection, nor is caused by it, is evident 

 from the fact that aggregation may take place when 

 there is no inflection of the tentacle. Some acids 

 will produce a rapid inflection but no aggregation. 



