1880.] 



MICROSCOPICAL JOURNAL. 



173 



chanical means as resorted to by some, 

 was to me quite unsatisfactory, and 

 in some cases even impracticable. 



I therefore tried some of the 

 methods recommended for bleach- 

 ing the wings of small moths. 

 That described by Chambers, in 

 the Canadian Entomologist, was 

 not a success in all cases, but 

 whether not properly tried, I can- 

 not say. 



I next tried the method for 

 bleaching the wings, published by 

 DimmocK ; and while this seemed 

 to be a success, so far as the bleach- 

 ing was concerned, the final mount- 

 ing did not always give satisfactory 

 results ; for when mounted dry, the 

 scales, although bleached, were not 

 sufficiently transparent to show 

 clearly the more obscure parts of 

 the structure, and when mounted in 

 Canada balsam, the entire wing was 

 rendered so transparent that only the 

 larger veins were visible, and I found 

 it extremely difficult to get rid of 

 the air-bubbles, which so readily 

 gathered under tlie concave por- 

 tions of certain minute wings. 



I next tried mounting in cold 

 glycerin ; after having been bleached 

 by Dimmock's method, the wings 

 were transferred to the slide direct 

 from the water in which they were 

 washed, then allowed to dry, which 

 was sometimes hastened by holding 

 the slide over the flame of a lamp. 

 When quite dry, a drop of glycerin 

 was added, and the cover at once 

 put on. Where the glycerin 

 penetrated around the edges so as 

 to completely saturate j)ortions of 

 the wing, the scales at once became 

 transparent, and the structure was 

 clearly apparent. 



The difficulty still remained to 

 replace the air under the concave 

 portions of the wings with glycerin, 

 so that it could come to and com- 

 pletely saturate every portion of 

 the wing, to the exclusion of all the 

 air. 



Recourse was now had to heat, 

 and by holding the slide over the 

 lamp tiU ebullition took place, the 

 glycerin was found to replace the 

 air without any injury to the wing- 

 structure ; and even in those re- 

 fractory cases when the glycerin 

 was allowed to boil for a consider- 

 able length of time, no injury what- 

 ever was done to the wing-mem- 

 brane. 



Permanent Microscopic Pre- 

 parations of Plasmodium.* 



By Simon H. Gage. 



The previously published me- 

 thods of making permanent pre- 

 parations of the motile or naked 

 protoplasmic stage of the Myxomy- 

 cetes are but two, so far as I know ; 

 and no method of getting the Plas- 

 modium in a desired position has 

 to my knowledge been published. 



The old method was to dry the 

 extended Plasmodium, the new is 

 to harden it with osmic acid. Both 

 these methods are defective, for 

 osmic acid changes the color of the 

 protoplasm, and drying causes it to 

 shrink as well as to change color. 



The following is a simple and 

 efficient method of extension and 

 preservation : Small pieces of the 

 rotten wood, on which the Plasmo- 

 dium is found, should be placed on 

 moistened microscope slides with 

 some of the Plasmodium touching 

 the slides. These should be on a 

 jDiece of window or plate glass, and 

 over the whole should be placed a 

 bell-jar, or other cover, to prevent 

 evaporation. After an hour or 

 more, the glass on which the slides 

 rest should be lifted up to see 

 whether the protoplasm has crawled 

 out upon any of the slides. If any 

 of the slides are satisfactory, lift on 

 the bell-jar and remove the pieces 



* Read before the Sub-section of Micro- 

 scopy of the A. A. A. S. 



