1899] MICROSCOPICAL JOURNAL. 3*71 



In the Fusulina the animal occupied the central spher- 

 ical shell for a time ; then a portion of its ameboid con- 

 tents spread out through an opening in the shell, forming 

 a belt about 3-100 mm. wide on the outside, its length 

 embracingslightly over one-half the perimeter of the shell. 

 This strip of living matter soon secreted a calcareous cov- 

 ering, which is the second chamber of the shell. The 

 third chamber is formed by a similar process along the 

 sides of the one already formed. A continual repetition 

 of this process completes the shell as we now find it fos- 

 silized in our limestone. 



Dana says "the cells of rhizopods are each occupied by 

 a separate animal." While it is possible for this to be the 

 case with some species of rhizopods, it is impossible with 

 the Fusulina, for an independent animal occupying the 

 central cells would have access to neither food nor oxy- 

 gen, after being enclosed by the outer portions of the 

 shell. The possession of the trough-like siphuncle indi- 

 cates the flowing of matter from chamber to chamber 

 along this course, as also do the thickened ends and 

 rounded corners of the septa where cut by this trough. 

 We know that an irritation of the bodies of conchiferous 

 animals produces an increase in the calcareous secretions 

 at the point irritated. Then the increased thickness and 

 rounded corners of the septa where cut by the stolon 

 passage may point to an irritation of the Fusulina at these 

 points, which could only come by a flowing of the proto- 

 plasm through the involute sinus. Only by a system of 

 circulation through the openings in the septa can an 

 ameboid animal secure the essential food and oxygen to 

 maintain life while inhabiting the recesses of a chambered 

 shell like the Fusulina cylindrica. — Kans. Acad. Sci. 



Moore's Bacteriology. — "It would be difficult to find 

 anywhere in the world, in the same number of pages, as 

 many important and useful suggestions." — A Critic. 



