OERSTED^ ON THE AGARICINI. 21 



filaments have, indeed, so thin, soft, and gelatinous a mem- 

 brane, that, when one tries to loose them from the soil, they 

 become, at the slightest contact, confluent into a mucous 

 mass, or a mucous net, with larger or smaller openings. Little 

 better success attends placing some of the soil overgrown by 

 the mycelium under the microscope, for one is not able to 

 apply a sufficiently high magnifying power. However, one 

 can, even by this plan, satisfy oneself of the existence of two 

 organs on the mycelium which cannot be seen by the un- 

 assisted eye. There thus present themselves numerous short 

 filaments, Avhich arise up vertically, and bear at their point a 

 globular cell. These filaments are thinner towards the 

 points, and appear to consist of three cells, of which the 

 lowest is only a little longer than broad, the next about twice 

 as long, and the uppermost much longer. Besides these 

 filaments one can discern another organ, much smaller, ajj- 

 pearing only just a little above the mycelium-filaments ; but 

 it is seen so indistinctly that one is not at all able to form a 

 conception of its structure. I tried, therefore, placing thin 

 glass plates over the soil, in order to get the mycelium to 

 become spread thereon. This succeeded so far that one could 

 get a very clear view of the growth and ramification of the 

 mycelium. The mycelium grows very quickly, and in the 

 space of a few hours the glass plate, 10mm. long and 6mm. 

 broad, became quite covered over by the delicate filaments, 

 which adhere as closely to the glass as if they were attached 

 with gum. Since the filaments hardly alter their form in 

 drying, these glass plates may be preserved without anv 

 further preparation as instructive specimens of the mycelium. 

 The mycelium so formed remained, however, sterile, and I 

 was almost about to give up hope of a successful result, when 

 I hit upon the idea that the mycelium spread upon the soil 

 would, perhaps, after being dried, more readily admit of 

 being separated and brought under the microscope in sueh a 

 condition that one could get a clear view of the organs seated 

 thereon. This proved itself indeed to be the case, since the 

 soft and mucous mycelium-filaments are prevented by drying 

 from falling together, and can be separated by a fine needle 

 into minute portions, which are quite free from particles of 

 earth, and thus can be examined under the microscope, with 

 the highest magnifying powers. The mycelium is now 

 softened, first with alcohol — when this precaution is not 

 observed, the view is made very indistinct by the quantity of 

 air-bubbles — and, after a drop of water is added, the indi- 

 vidual filaments and the organs seated thereon quickly assume 

 the same nature which they had previous to being dried. 



