152 SUMMARY OF CURRENT RESEARCHES RELATING TO 



such as AglaopJienia pluma or Plumularia setacea, it must be allowed 

 to remain some hours until the polypides are fully extended, Klein- 

 enberg's fluid must then be introduced by means of a dipping-tube. 

 It may be allowed to flow over the specimen in a continuous stream, 

 until the whole of the water assumes a golden yellow colour. The 

 reagent causes instant death, so that the specimens may be transferred 

 immediately to 60 per cent., and afterwards to 75 per cent, alcohol, 

 allowing them to remain in each solution for some hours. Keep 

 in 90 per cent, alcohol. From four to six minutes' immersion 

 in Martindale's picrocarmine staining fluid is sufficient to stain 

 specimens killed by either of the above methods. 



Mounting Pollen as an Opaque Object.* — W. Blackburn gives 

 directions for mounting pollen dry upon the anther from which it has 

 escaped. For collecting and drying the anthers, the flowers should 

 be gathered when full-blown, just before they begin to fade, and the 

 stamens then cut with fine scissors a short distance from the anthers, 

 the latter being allowed to fall upon clean writing paper, when a selec- 

 tion may be made with a pocket-lens of the specimens most suitable for 

 preservation. Folding the paper without pressure, place the packet 

 in a box, where the author lets it remain in oblivion for twelve months 

 or perhaps two years. In the case of large anthers, such as the Lilium 

 auratum, it may be advisable to lay them on a piece of blotting-paper, 

 inside the writing-paper, in order the better to absorb moisture, care 

 being taken when mounting, to remove any adhering fibres of the 

 blotting material with a needle. 



Thin metal and bone cells may be used for mounting. The metal 

 ones may be either of brass or block tin. For small anthers, such as 

 those of Ranunculus aquatilis, the ordinary 1/2 in. brass cells are suit- 

 able. For larger anthers, or groups of stamens and anthers, such as 

 may be made from the Ahutilon, 5/8 in. and 3/4 in. bone cells are 

 the best. Bone is much preferable to metal for its adhesive capacity 

 when affixed to glass, and the bone cells usually sold have their 

 surfaces " truer " than those of metal. For cement use " quick- 

 setting " gold size. 



When about to mount the anthers, paint the bottom of the cell 

 with " matt-black," using the turntable, so as to distribute it evenly 

 over the glass. When the " black " is partially dry, place the anthers 

 upon it in suitable positions, and gently press them with a blunt 

 needle so as to secure their adhesion to the cement. The best effect 

 will be produced when the anthers are arranged in the centre of the 

 cell with the stamens directed on one side, as in their natural position. 

 This, however, may be left to the taste of the mounter ; and in many 

 cases no arrangement of this kind will be required, as one or other 

 will be found large enough to fill the cell. When there is found to 

 be a deficiency of pollen on any of the anthers after mounting, some 

 pollen may be taken on the point of a needle from other anthers and 

 placed in position on the bare parts, when gently breathing upon it 

 will fix it. 



* Micr. News, iii. (1883) pp. 297-9. 



