Mabch is, 1910] 



SCIENCE 



423 



are very close together, from two millimeters 

 to several millimeters apart. If the spores 

 were not shot for some distance from the sur- 

 face of the giU of the agaric, or tube of the 

 polypore, they would fall upon the surface 

 of the hymenium, and because of their ad- 

 hesiveness could not escape. If they were 

 shot too far they would strike the hymenium 

 opposite and adhere. In Agaricus campestris 

 they are thrust horizontally for about 0.1 mm. 

 and in Amanitopsis vaginata about 0.2 mm. 

 They then fall very slowly, and after passing 

 below the gills are easily wafted away by even 

 slight air currents. 



The deliquescing Coprini represent another 

 type of fruit body from that of other Hymen- 

 omycetes in the very high specialization which 

 has taken place in the adaptations for spore 

 dispersal. Goprinus comatus, the shaggy mane 

 mushroom, will illustrate this type. The 

 pileus is large and cylindrical, so that the 

 broad, long gills stand vertically between it 

 and the stem. The gills are very close to- 

 gether. At their edges are numerous project- 

 ing large cystidia which are connected with 

 those of adjacent giUs. If the basidia and 

 spores matured simultaneously over the entire 

 surface of the gills, or over any considerable 

 portion, as in other agarics, very few of them 

 would ever reach the outer air, since they 

 would lodge on the surface of the giUs or upon 

 the numerous large cystidia on the sides of the 

 gills. The basidia and spores are matured, 

 first over a narrow zone occupying the edge 

 at the lower end of the gills. The cystidia on 

 the edges of the gills are dissolved by auto- 

 digestion. When these spores are shot off they 

 readily reach the air below by falliag. This 

 now sterile part of the gill, by autodigestion, 

 is reduced to a liquid condition. It is black- 

 ened probably by an oxydase which imites 

 with certain substances. It is covered by a 

 thin filTTi and by evaporation becomes thinner, 

 so that the spores from a narrow zone next 

 above can readily fall down in the wider 

 spaces thus formed, and so on. At the same 

 time the pUeus begins to expand more rapidly 

 at the margin so that by the time the ink 

 drops begin to fall they are out of reach of 



the falling spores. In contradistinction to the 

 belief held by some that the spores of the 

 Coprini are mixed with the inky fluid and 

 that they are then disseminated by insects," 

 the author believes that under normal condi- 

 tions very few if any spores are caught in the 

 liquid, and that the spores are anemophilous. 



The adjustments of the fruit body of Go- 

 prinus comatus are as follows : (1) A large 

 number of gills with a very great spore-bear- 

 ing surface, (2) a thin pileus, thus economiz- 

 ing energy in its development, but incapable 

 of expanding and lifting the weight of the 

 gills, (3) the spacing of the basidia by para- 

 physes assuring the free projection of the 

 spores, (4) the nearly simultaneous expulsion 

 of the spores from all of the basidia of a nar- 

 row zone at the lower edge, (5) the autodiges- 

 tion of this zone to provide space for the fall 

 of the spores shot from the basidia of an ad- 

 jacent higher zone, and so on, (6) the grad- 

 ual expansion of the pileus from its margin 

 inward after autodigestion of the sterile parts 

 of the gills removing the fluid parts from in- 

 terference with the fall of spores from the suc- 

 cessive zones of spore ejection, (7) the con- 

 tinued elongation of the stipe lifting the gUls 

 higher so that the spores are more easily 

 caught by air currents. 



These adjustments the author believes indi- 

 cate a higher degree of specialization on the 

 part of the Coprini and that, instead of being 

 a primitive group as suggested by Massee^ 

 (p. 130), they represent the highest develop- 

 ment and specialization of the Agaricini. 



In many of the Ascomycetes, as has been 

 long known, the spores are squirted out from 

 the ascus. In Peziza repanda, with narrow 

 cylindrical asci, the spores are shot out in a 

 chain along with some of the liquid. The dif- 

 ference in momentum given the successive 

 spores of the chain, together with the spon- 

 taneous segmentation of the liquid cylinder 

 in which they are imbedded according to a 

 well-known physical law, separates the spores 

 in the air so that they are wafted away by the 



1 See Fulton, Ann. Bat., III., 215, 1889. 

 -Massee, Geo., "A Revision of the Genus Go- 

 prinus," Ann. Bat., X., 125-184, pi. 10, 11, 1896. 



