1881.] 



MICKOSCOPICAL JOUKNAL. 



205 



also require a pocket lens ; a ham- 

 mer, and two or three mason's chi- 

 sels. If you carry only one chisel, 

 and have to face hard rocks, dur- 

 ing the first fifteen minutes you may 

 find yourself half helpless for the rest 

 of the day, by the turning or breaking 

 of your chisel point. Crustaceous Li- 

 chens are gathered by cutting away a 

 piece of the stone on which they grow, 

 and the other forms accordingly. You 

 will further need a botanical box, or 

 small basket, and many of the speci- 

 mens will require wrapping in paper, 

 to prevent rubbing, in carrying them 

 home. Take particular note where 

 the plants are gathered, so that the 

 locality in a word or two can be writ- 

 ten upon the sheets when they are 

 mounted. 



On reaching home with your ga- 

 therings, the first thing to be done is 

 to press and dry the foliaceous and 

 fruticulose forms. Then mount the 

 whole on slips of paper, with gum or 

 glue. We find nothing to answer this 

 purpose better than a thick solution 

 of gum Arabic, with a few drops of 

 glycerin in it, to modify its brittle- 

 ness. On each slip of paper record 

 the place where gathered, with date, 

 and collector's name. The plants 

 may now be placed together on one 

 side without danger of confusion, and 

 be brought out one by one for deter- 

 mination or study as you may have 

 leisure and opportunity. In the in- 

 vestigation of Lichen tissues and spo- 

 ridia, and the determination of spe- 

 cies, there will be required a com- 

 pound microscope, with a magnifying 

 power of from 60 to 400 linear mea- 

 surement (one-inch and quarter-inch 

 objectives with A and C eye-pieces) ; 

 also, a double lens for the eye. Some 

 use an ordinary watchmaker's eye- 

 glass. One of these glasses mounted 

 in a pair of spectacle frames, would 

 be very useful for the lichenologist. 

 A small thin dissecting knife, and so- 

 lutions of iodine, hydrate of potash, 

 and hypochlorite of lime. The ma- 

 . king up, with the application of these 

 reagents, are fully described in 



Leighton's Lichen-Flora. The iodine 

 acts more or less upon the gelatina- 

 hymenea of the paraphyses and asci, 

 turning them blue, yellow, or vinous- 

 red. The hydrate of potash dissol- 

 ves the gelatina-hymenea, and shows 

 the hymenium more clearly under 

 the microscope, beside swelling the 

 spores and paraphyses up to their full 

 size. The hydrate of potash and hy- 

 pochlorite of lime are also used on 

 the Lichen-thallus as tests ; and, as 

 such, are of considerable value and 

 importance. On account of the che- 

 mical elements in the thallus, it re- 

 acts in certain colors, or not, on the 

 application of these reagents. This 

 reaction, or non-reaction, is a great 

 help in the determination of species. 

 The method of examining the apo- 

 thecium or other organ of the Lichen, 

 is to place the plant on the table, 

 then, with the lens to the eye, place 

 the knife on the top of the organ 

 about midway, and cut it straight 

 down. Cut down a second time close 

 to the first, and thus get out a section 

 as thin as you possibly can ; place it 

 in the compressor, or upon the glass 

 stage of the microscope, moisten it 

 with clear water, and put on a thin 

 glass cover. Now you may examine 

 the section, and if you have a good cut, 

 you will have all the parts of the apo- 

 thecium before you. You must now 

 observe the color and form of the 

 hypothecium, the character of the 

 paraphyses, with the color of their 

 apices ; also, the shape of the asci, 

 and the number, color, form and 

 septa of the spores. You may now 

 run in a drop of iodine, watch and 

 carefully note the results. After this, 

 run in a drop of the hydrate solution, 

 which will annul the action of the 

 iodine — consequently it must always 

 be used after it, where both are re- 

 quired. This does not generally des- 

 troy any natural color, but it will 

 show you, if you have obtained a cor- 

 rect idea of the several points just 

 named above. When you have thus 

 examined the apothecium, and the 

 spermogones if you can find any ; and 



