10 THE AMERICAN MONTHLY [January, 



Leidy's illustrations will be almost sure to mislead. After looking at his 

 figui-e oi Amceba protetis^ you go hunting around on the slide for a cannon- 

 ball, when you ought to be on the watch for the finest shot. I remember, 

 when it was first pointed out to me, I couldn't help exclaiming, in some dis- 

 gvist, Is that an Amoeba } It seemed utterly insignificant alongside the mam- 

 moth illustration. Expect them, then, to seem minute and trifling, and re- 

 member to put on a good high power before you pass over an3'thing that 

 bears any resemblance to a rhizopod. Especially will this be needed when 

 you set to work to determine the genus, the lines and markings of the shell 

 being very delicate in many cases. It may do to use the binocular and the 

 ^-inch for a Difflugia, but when it is a Nebela or an Assulina, you want the 

 monocular tube, the Ith or the ^^th objective, and central illumination of the 

 very best kind. 



Next, about collecting the specimens. Begin with the best habitat of all, 

 and that is sphagnum, or bog-moss. You will get more forms out of a 

 sphagnum swamp than from half a dozen other localities. And they will be 

 clean and nice ; and if the moss is just put in a candy jar with some of the 

 bog-water, and covered with a glass plate to exclude the dust, they will keep 

 in good condition for months if not exposed to the direct rays of the sun. 

 But you won t Ji7id the fo7'ms in all sphagnum. If at first you don't suc- 

 ceed, however, do as the proverb directs. Keep at the sphagnu??!^ gather- 

 ing it from other localities, until your search is rewarded, as it surely will be. 

 And if you can't find any sphagnum, go to any florist in the city and buy 

 some. They almost always have it on hand, and from such a quarter I got 

 most beautiful specimens of Hyalosphenia papilio years ago, finer than I 

 have ever found since. The moss was in an old barrel in the florist's yard, 

 where it had lain for weeks, vet many of the rhizopods were alive. It will 

 please you to learn that that sphagnum came from New Jersey. 



Lastly, as to preserving and mounting. Carbolized water makes an ex- 

 cellent medium, a few di'ops of the strongest solution being added to a six or 

 eight-ovmce bottle of material, and the whole thoroughly shaken. The rhizo- 

 pods may then be mounted directly on a slide, without any cell, the cover 

 being fastened down by successive rings of Brown's cement, or a thin cell of 

 this cement may be made first, and the cover applied as before. 



The Rhizopods, therefore, are so easily obtained, kept, preserved, and 

 mounted ; they are so beautiful and diverse ; and they offer so many points 

 of interest that the subject is a most fascinating and profitable one for the 

 micioscopist ; and I trust that this brief and imperfect sketch may be the 

 means of inducing all of you to engage in this study at some time or other. 

 Whether you discover anything new or not, you will surely be repaid for all 

 the labor you may put upon them. 



The staining of animal and yegetable tissnes.* — I. 



By ARTHUR J. DOHERTY, 



MANCHESTER, ENGLAND. 



SINGLE-STAINING. 



The object of the present paper, which is addressed to professed biologists 

 as well as to dillettanti., is twofold : — firstly, to record the results of my own 

 extensive researches into the properties of staining reagents ; and, secondly, 

 to place before the microtomist, in a condensed form, an account of various 



* Reprinted from Transactions of Manchester Microscopical Society, 1886. 



