HARDWICK&S SCIENCE-GOSSIP. 



sections must be placed in a solution of equal parts 

 of alcohol and water, and kept there until wanted. 



Stainingin Carmine. — Transfer the required sections 

 from the alcohol and water into the "mordant" 

 diluted as directed, and leave them there overnight ; 

 in the morning re-transfer them into the diluted 

 carmine dye, leaving them there say an hour or so, 

 when they must be well washed, first in clean dis- 

 tilled water acidulated with thirty drops of nitric 

 acid to the pint, and secondly in clean distilled water 

 only, and finally preserved in alcohol for a couple of 

 hours or until wanted. 



Staining in Green Aniline, and Mounting. — Take 

 the carmine-dyed sections and place them in the green 

 aniline dye, leaving them there at least twelve hours, 

 after which they must be taken out one by one as 

 each will have to be mounted as rapidly as possible : 

 as each section is taken out place it for a few seconds 

 only in clean absolute alcohol, washing very little of 

 the green dye out as it is very fugitive, after this, 

 transfer it into oil of cloves for such time only as will 

 render the section translucent. By this time more of 

 the green will have washed out, then take the section 

 out, place it on a glass slip with the least possible 

 quantity of the oil of cloves, as this evaporates most 

 slowly ; add balsam dissolved in benzole and cover 

 with a thin glass circle or square as preferred. Leave 

 the slides for a day or so, by which time a large pro- 

 portion of the benzole will have evaporated, when the 

 slides can be dried off by placing them, as I do, 

 on the top of a hot-water cistern with pieces of 

 wood under them to moderate the heat if too hot, 

 and leaving them there for a week or more as may be 

 found requisite. By adopting this plan all risk of 

 bubbles is avoided, and the balsam can be hardened 

 to any degree, even until it becomes hard and brittle, 

 allowing the cover to flake off on the least jar. 



To still further assist your readers in preparing 

 good specimens of double-stained vegetable sections, 

 I will add the following hints. 



The sections if possible should be cut while 'still 

 moist and never be allowed to dry, as drying will in 

 many instances quite spoil the tissue ; pith, for in- 

 stance, will often crack and spoil all sections taken 

 from it ; moreover it is much easier to cut clean good 

 sections when the material is moist than if the same 

 be dry. 



In transferring sections from one solution to another, 

 I never use forceps, as it would be impossible to do so 

 without very often spoiling the specimens, however 

 light a hand I might have ; I use instead a flat spoon 

 or ladle, made by beating out the end of a piece of 

 one-eighth inch brass wire and well smoothing the 

 edges. Platinum would be preferable for use with 

 the acidulated water but is expensive ; in this case I 

 use a glass stirring rod, but this is awkward to manage; 

 a camel-hair pencil can be employed if preferred. 



Care must be taken to have all the solutions 

 thoroughly clean ; they must be well filtered every 



now and then ; this rule does not apply so stringently 

 with the solution of chlorinated soda, as this gets 

 dirty by being used, besides which the sections get 

 well washed when taken out of it. 



Occasionally the carmine dye and mordant will be 

 found too weak if used diluted in the proportion as 

 directed, as some sections take the dye very much 

 better than others ; in such cases it will be necessary 

 to increase the strength of both the mordant and the 

 dye ; it is no use increasing the strength of the dye 

 only, as the excess colour will not be permanent but 

 will wash out immediately the section is placed in the 

 water ; the fixing of the dye is entirely dependent 

 upon the strength of the mordant employed. Carmine 

 requires a mordant when employed with vegetable, 

 but not with animal tissue. 



I have not properly tried it, but I have no doubt 

 that a one per cent, solution of alum would answer 

 as a mordant in place of the kind I employ, which is 

 really nothing more or less than a solution of acetate of 

 alumina, but I am not quite sure where I could obtain 

 this chemical ready prepared. 



In conclusion I may say I think that if any of your 

 readers will give this plan of double-staining a fair 

 trial, they will find themselves able to prepare slides 

 of double-stained vegetable sections which will give 

 them every satisfaction ; they must however bear in 

 mind that some preparations will be found much 

 more effective than others, though the process em- 

 ployed be exactly the same in all cases. As a rule, 

 when slides are prepared for sale, the more effective 

 and showy preparations have naturally the preference. 



H. M. 



NOTES ON SOME OF OUR SMALLER 



FUNGI. 



By G. E. Massee. 



THE species of Trichia when young resemble 

 minute globules of cream ; afterwards they 

 become dry and look like miniature puff-balls, sessile 

 or stalked ; the peridium is irregularly torn at the top, 

 spores and threads usually saffron or bright yellow. 

 The spiral threads at once mark the genus. T. chry- 

 sosperma, common on rotten wood, bark, &c, is most 

 frequent, crowded, subsessile, more or less com- 

 pressed, at first white, afterwards cinnamon yellow ; 

 spores and threads yellow, the latter short and with 

 pointed ends ; spiral markings strong. This genus 

 belongs to the order Myxomycetes, the members of 

 which are distinguished from all other plants by the 

 absence of a cell-wall during their vegetative period ; 

 it is only on the formation of fruit that the protoplasm 

 breaks up into pieces, each surrounded by a cell-wall. 

 This exceptional gelatinous early condition has led to 

 much difference of opinion as to their true position, 

 and Professor de Bary at one time considered them 

 as animals closely related to the Gregarines, but in 



