1882.] 



MICEOSCOPICAL JOUENAL. 



93 



spirit lamp, add the distilled water 

 and filter. 



For the green stain : anilin green, 

 5 gr.; absolute alcohol, i oz. 



Very beautiful results are obtained 

 from the following method of using 

 these preparations together. The 

 section is immersed from five to ten 

 minutes in the green, and then passed 

 at once into the carmine, in which 

 it remains from one to three minutes, 

 the process being carefully watched 

 in order that the carmine may not 

 stain too deeply. It is then thoroughly 

 washed in absolute alcohol, passed 

 through oil of cloves, and then 

 mounted in solution of balsam in 

 benzole. The use of the benzole- 

 balsam is important, as it has a de- 

 cided action in fixing the stain, due 

 to the presence of benzole. Two or 

 three drops of each liquid suffice, 

 and the whole operation is performed 

 upon a glass slide, or in a watch- 

 glass. 



The woody parts of the section 

 take a rich carmine, shading into 

 orange, while the pith and light cel- 

 lular tissue are stained a bright 

 orange-yellow. In a section (trans- 

 verse) of the leaf-stem of the sago- 

 palm, the outer cells, which are 

 smaller and more compact than the 

 more central ones, were dyed a rich 

 orange-yellow, and their nuclei a 

 bright carmine. The cuT^ious large 

 ducts in the central portion of the 

 stem, which, as a system, form in a 

 "transverse section a figure like the 

 Greek capital omega, take a pleasing 

 variety of shades, the cells around 

 the edges being a bright orange, the 

 central cells shading down to deep 

 carmine. These sections of the mid- 

 rib of the sago-palm, by the way, are 

 beautiful objects stained or unstained, 

 and one of the best examples of 

 curious cell arrangements to be found 

 anywhere. 



The action of the dyes made from 

 the above formula is quick and cer- 

 tain, and the effects very satisfactory. 



T. W. Taylor. 



-o- 



A Food Habit of Difflugia Py- 

 riformis. 



BY DR. A. C. STOKES. 



It is well known that the orange- 

 colored, Actinophrys-like rhizopod 

 Vampyrella later-itia, feeds upon 

 the cell-contents of spirogyrae, but 

 has it been observed that the shell- 

 bearing form Difflicgia pyrifo7'7nis has 

 a similar habit ? Such, indeed, is the 

 case, and Difflugia, if more deliber- 

 ate than Vampyrella, is quite as vo- 

 racious. I have seen one individ- 

 ual despoil four spirogyra-cells of 

 their contents in about three hours 

 and have its activity thereby increas- 

 ed, although the creature must have 

 been gorged. 



Having come to rest upon a fila- 

 ment of the alga, the rhizopod perfo- 

 rates a cell-wall, whether. by pressure 

 alone or in some other way does not 

 appear; probably, however, by diges- 

 tion, since, when the spirogyra-cell is 

 seized by its free end, it is drawn 

 into the mouth of the shell, and pre- 

 sumably comes in contact with the 

 endosarc, and when taken in any 

 other position the whole cell is forced 

 into a curve, so that the shell rests 

 upon the convexity, the upper wall 

 being drawn within the mouth and 

 marked by diverging wrinkles. 

 Through the opening, pseudopodia 

 enter and, uniting, seem, from the 

 first, to form a sarcode lining between 

 the cellulose wall and the chlorophyll 

 band. As the sheath of animal pro- 

 toplasm slov/ly advances, the chloro- 

 phyll band falls and, losing its dis- 

 tinct, crenated outline, becomes par- 

 tially disintegrated and is borne to- 

 ward the shell by a reverse central 

 current. When the cell is half-emp- 

 tied, the sarcode envelope is more 

 distinctly developed, the free ex- 

 tremity being especially thick. Fi- 

 nally, the whole slowly disappears 

 into the shell, and pseudopodia of the 

 ordinary form then explore the empty 

 cell andgiiick up any fragments that 

 may remain. 



Trenton, N. J. 



o 



