The Microscope. 53 



ribbons which resemble, somewhat remotely, the pseudopodic 

 prolongations of the Rhizopods, although in action and in 

 function there is not even a remote resemblance. These pro- 

 trusions are usually abundantly developed, and the entire field 

 may be filled with corpuscles in this condition. But the re- 

 markable fact in connection with them is that the}^ all are in 

 motion. A protoplasmic thread from the surface of a corpuscle 

 may be as long as the corpuscle is wide, while it may extend 

 and twist and writhe and quiver like a living thing, and if the 

 microscopist is looking at his own blood the sensation will 

 probably be a new one, and not altogether agreeable, the little 

 drops and the delicate threads trembling and shaking with an 

 uncertain, irregular movement that is as fascinating as it is 

 suggestive. The movements are not pseudopodic ; they are not 

 voluntary ; the}^ seem to be pedetic rather than otherwise, to be 

 caused as the Brownian movements are caused, by thermal or 

 electric currents. But in the corpuscles that show these kinds 

 of protrusions and these kinds of movements, the reticulation 

 of the protoplasm is seldom to be seen distinctly ; in them it is 

 seldom to be seen at all. Such corpuscles often become what 

 have been called " ghosts," finally appearing in the field as color- 

 less, empty rings, like the ghosts of corpuscles. 



With those globules, however, whose knob-like protusions do 

 not prolong themselves into motile beads or threads, the reticu- 

 lation becomes beautifully and conspicuously visible within two 

 hours, sometimes within half an hour, after the application of 

 the potassium solution. The corpuscles grow gradually paler, the 

 knobs are withdrawn, the surface becomes smooth and rounded, 

 and the fine meshes of the protoplasmic net-work become grad- 

 ually prominent, forming as pleasing and as instructive an object 

 for the microscopist with an evening's leisure as can be 

 imagined. 



The meshes are exceedingly fine and the threads forming 

 them exceedingly delicate, but at the points of intersection a 

 thickening is produced that ma}- be taken as so man}^ guides 

 whose position will direct one to the connecting threads. 



With the proper objectives these appearances are readily 

 observable. Yet, although the ease with which the reticulation 

 may be seen is great, the statement should not lead the reader 

 to think that the work is only a bit of child's play, and as easy. 



