V] 



OF GLOBULES OR BEADS 



235 



and lies free as a protoplasmic cylinder in the interior of the cell. 

 Thereupon it immediately shews signs of instability, and commences 

 to disrupt. It tends to gather into -spheres, which however, as in 

 our illustration, may be prevented by their narrow quarters from 

 assuming the complete spherical form ; and in between these 

 spheres, we have more or less regularly alternate ones, of smaller 

 size*. Similar, but less regular, beads or droplets may be caused to 

 appear, under stimulation by an alternating current, in the proto- 

 plasmic threads within the living cells of the hairs of Tradescantia. 

 The explanation usually given is, that the viscosity of the proto- 



Fig. 70. Phases of a Splash. (From Worthington. ) 



plasm is reduced, or its fluidity increased ; but an increase of the 

 surface tension would seem a more likely reason f. 



We may take note here of a remarkable series of phenomena, 

 which, though they seem at first sight to be of a very different 

 order, are closely related to the phenomena which attend and 

 which bring about the breaking-up of a liquid cylinder or thread. 



In some of Mr Worthington's most beautiful "experiments on 



* The intermediate spherules appear, with great regularity and beauty, whenever 

 a hquid jet breaks up into drops; see the instantaneous photographs in Poynting 

 and Thomson's Proiierties of Matter, pp. 151, 152, (ed. 1907). 



■]■ Kiihne, Untersiwhungen iiber das Protoplasma, 1864, p. 75, etc. 



