1892.] MICROSCOPICAL JOURI^AL. 51 



A Beautiful Rliizopod. 



By CHAS. W. smiley, 



WASHINGTON, D. C. 



At the lowest point in the animal kingdom stand the protozoa. Of 

 these there are tour classes : I, thcMonera (without any organs) ; II, the 

 Rhizopoda (having a nucleus and outer layer of sarcode) ; III, the 

 Gregarinida (an ovate, animal parasite) ; and IV, the Infusoria (hav- 

 ing a definite shape and usually one or more mouths), holding the 

 highest place in the quartette. 



The Rhizopods are rarely visible to the naked eye, but they abound 

 everywhere if there is moisture or dampness — in ponds, in lakes, in 

 swamps, in sea, in ocean. Some grow in salt water and some in fresh. 

 Leidy has v\'ritten only upon the fresh-water forms. Ponds and ditches 

 may be skimmed for specimens with a small tin dipper and the super- 

 ficial ooze transferred to a bottle to await examination. Often speci- 

 mens may be scraped up from wet ground with the blade of a knife, 

 their presence being betrayed by the green algous material which is 

 plainly visible. Their pursuit is feasible at nearly all times of the year, 

 even in winter, if vegetation is not completely covered by ice and snow. 



At this time of year our readers may well begin the collection of 

 specimens, preserving them as described by Leidy and other author- 

 ities. The Rhizopods are classified by Hitchcock (Riverside Natural 

 History) in (i) Lobosa, (3) Radiolaria, (3) Heliozoa, (4) Reticularia. 



Of the Heliozoa, or sun animalcules, he says that they are very beau- 

 tiful, being mostly spherical and floating forms. A few are attached by 

 long pedestals. They put out delicate rays in all directions from the 

 centre, often exceeding the diameter of the body in length. 



The most common of the Heliozoa is Actinophrys sol^ which occurs 

 in pools of standing water almost everywhere among floating plants. 

 Under a low power of the microscope it is a colorless, spherical body, 

 4-iooth to i3-iooth mm. in diameter. The great number of delicate 

 spines can be seen projecting from the body to 3 or 4 times its diameter. 

 But the most beautiful form of this order is Clathrulina elegans. Its 

 capsules become yellow with age, presenting a rich golden appearance, 

 and it is often found in ponds and ditches. 



If our readers will search for these forms and report their finds, we 

 shall be glad to publish the list in May or June. By means of the 

 plates in Leidy's Fresh-Water Rhizopods they may be identified by any 

 careful observer. Our attention is drawn at this time to ClatJiJ-ulina 

 by the fact that it has recently been discovered, for the first time in 

 Asia, by Mr. Simmons, our esteemed correspondent, the secretary of 

 the Calcutta Microscopical Society. On the occasion of his making 

 known his find, he presented not only specimens but some elegant 

 illustrations, which Mr. Robert W. Smiley has redrawn for presenta- 

 tion with this paper. 



At the December meeting in Calcutta, J. Wood-Mason gave a re- 

 sutnc from German and Russian authorities of our knowledge of Cla- 

 thrulina elegans^ which we reproduce below, much of it being new to 

 English-speaking people : 



" This wonderful and delicate heliozoan presents itself under a low 

 (^-inch) power of the microscope as a simple drumstick-shaped body 

 consisting of a long and thin cylindrical stalk, which at one end is sud- 



