1880.] 



MICEOSCOPICAL JOUKNAL. 



191 



creased only very gradually, other- 

 wise vapor of alcohol biibljles will 

 make their appearance in them. 

 A small ring of Brnnswick black 

 may be made in the inside of the 

 cell, to which when thoroughly dry, 

 the object may be fastened witli a 

 very little liquid marine glue. In 

 this case both sides of the leaf can 

 be seen, which is often desirable. 

 In all opaque mountings a minute 

 aperture should in some way be 

 left open into the inside of the cell, 

 so that it shall not be hermetically 

 sealed uj). This little precaution 

 will save an innumerable number 

 of failures. 



The collector in Florida will not 

 fail to secure a supply of the leaf 

 stems of the castor oil plant {Rici- 

 nus communis). In regions beyond 

 the influence of frosts, this plant 

 grows continuously from year to 

 year, and becomes quite a tree. It 

 is only in such a growth that the 

 spiral tissue of the fibro-vascular 

 bundles is fully perfected. The 

 castor oil plants grown in our cli- 

 mate during one short season, will 

 furnish very little spiral tissue, 

 mostly spotted ducts and scalari- 

 f orm cells. There is no more beau- 

 tiful object for multiple staining 

 than thin longitundinal sections 

 through the woody fiber, the vas- 

 cular tissues, and the pith cells of 

 well matured leaf -stems of the cas- 

 tor oil plant. I will briefly de- 

 scribe my process of making these 

 stainings. After being decolor- 

 ized in chlorinated soda, the sec- 

 tions may be left for half a day or 

 more in a solution of carmine in 

 water containing a few drops of 

 aqua ammonia ; then for half an 

 hour in a rather weak solution 

 of extract of logwood in alum 

 water, and finally 10 to 15 minutes 

 in a weak solution of anilin violet 

 or blue in alcohol. From this they 

 can be carried through absolute 



alcohol into turpentine, and mount- 

 ed in balsam at any time thereafter. 

 If successful in this staining you 

 will have the pith cells in red, the 

 spiral tissue in blue, the wood cells 

 in purple and the stellate crystals in 

 green or yellow. 



But the chief objects of interest 

 to the microscopist in the vegetation 

 of Florida, are the insectivorous 

 plants. ISTot only are they more 

 abundant, and, as I think, more 

 perfectly developed in the central 

 lake regions of Florida, but some 

 varieties are found there differing, 

 it seems to me, from any found else- 

 where. I desire particularly to 

 mention one which I discovered, 

 and which perhaps might be entitled 

 to rank as a new species. 



In a lagoon-like basin at the side 

 of a small lake near Lake H&rris, in 

 water from two to three feet deep, 

 I found numerous specimens of the 

 insectiverous plant known as the 

 Drosei^a or sun -dew, growing thrifti- 

 ly and floating about among the 

 scattered water-weed*!, without any 

 attachment whatever, indeed with 

 veiy little root of any kind, the 

 dead leaves that hung down in the 

 water seeming both to buoy it up 

 and to hold it upright. This plant 

 differs from all the described species 

 of Drosera, so far as I have been 

 able to ascertain, in having an up- 

 right, leaf -bearing stem from four to 

 five inches long, in floating free on 

 the water, and in having unusually 

 long, vigorous and numerous leaves. 

 As I never found this floating Dro- 

 sera in any other location, and as 

 there was an abundance of the ordi- 

 nary Drosera longifolia growing 

 on the adjoining shore, I could not 

 resist the suspicion that at this 

 very spot in some past time 

 a plant of the longifolia had 

 by accident become uprooted, and 

 floated out on the water — that find- 

 ing it could capture insects even 



