14 INTRODUCTORY 



Collection and Care of Slime-Mould Material 



On this subject a word may here be appropriate. As just now inti- 

 mated, specimens may be taken at the appropriate season in almost 

 any or every locality. Beginning with the latter part of May or first 

 of June, in the Northern states, plasmodia are to be found everywhere 

 on piles of organic refuse: in the woods, especially about fallen and 

 rotting logs, undisturbed piles of leaves, beds of moss, stumps, by the 

 seeping edge of melting snow on mountain sides, by sedgy drain or 

 swamp, nor less in the open field where piles of straw or herbaceous 

 matter of any sort sinks in undisturbed decay. Within fifty years 

 tree-planting in all the prairie states has greatly extended the range 

 of many more definitely woodland species, so that species of Stemo- 

 nitisj for instance, are common in the groves on farms far into Ne- 

 braska and Dakota. In any locality the plasmodia pass rapidly to 

 fruit, but not infrequently a Plasmodium in June will be succeeded 

 in the same place by others of the same species, on and on, until the 

 cold of approaching winter checks all vital phenomena. The process 

 of fruiting should be watched as far as possible, and for herbarium 

 material, allowed to pass to perfection in the field. 



Specimens collected should be placed immediately in boxes in such 

 a way as to suffer no injury in transport; beautiful material is often 

 ruined by lack of care on the part of the collector. Once at the 

 herbarium, specimens may be mounted by gluing the supporting mate- 

 rial to the bottom of a small box. Boxes of uniform size and depth 

 may be secured for the purpose. Some collectors prefer to fasten the 

 specimen to a piece of stiff paper, of a size to be pressed into the box 

 snugly, but which may be removed at pleasure. Every pains must in 

 any case be taken to exclude insects. Against such depredators occa- 

 sional baking of the boxes on the steam radiator in winter is found to 

 be an efficient remedy. 



For simple microscopic examination it will be found convenient to 

 first wet the material with alcohol on the slide, then with a weak 

 solution of potassic hydrate, to cause the spores and other structures to 

 assume proper plumpness. A little glycerine may be added or run 

 under the cover if it is desired to preserve the material for further or 

 prolonged study. For permanent mounting nothing in most cases is 



