1897] MICROSCOPICAL JOURNAL. 381 



At this juncture, the metallic gratiug is brought into 

 use. At the point where the two lines intersect i.s [)laced 

 a bit of metal. Then with the grating the distance down 

 to the point occupied by the foreign substance, which is 

 necessarily directly under, the point of intersection is 

 measured, the line being projected parallel with the base 

 line of the fluorometer. 



The Sporular Development of the Amoeba Villosa, 



By J. C. SMITH, 



New Orleans, La. 



[Read before the A. M. Society, 1897.] 



In April, 189Y, the writer secured some decayed leaves 

 from a pond in the Audubon park in New Oileans, and 

 on scraping a portion from one of the leaves, placed it 

 under a cover-glass, and then examining it witli a -| inch 

 objective, the field was seen to be filled wit!) a number 

 of Amoeba villosa, Leidy. Some of the specimens were 

 active, some were apparently on the threshold of eucyst- 

 ment, while others had already entered that state. The 

 field, fortunately, was entirely free from other forms of 

 Amoeba as well as of the troublesome Parara;ecium. 



For awhile the field was thoroughly examined, and the 

 writer noticing something unusual about the Ainceba, con- 

 centrated his attention on one of the forms thif had be- 

 come quiet, and evidently about to become encysted. Thi- 

 specimen measured 1-125 inch, displayed the posterior wd I 

 covered with the villous processes which are ili.-r-;nostir of 

 this species. The endoplasm contained a nun cr of lin- 

 ear bodies and some food-balls already change I in color. 

 The contractile vesicle was large and acti\ •, and instead 

 of the usual nucleus, there were from ten to fifteen nu- 

 clear looking bodies that moved freely in the endoiilasni 

 in unison with a slight contraction and expansion of the 

 body. These nuclear looking bodies were evenly dis- 



