NATURAL SCIENCES OF PHILADELPHIA. 215 



threads dying away after the tubers were mature so in the com- 

 mon agarics we have the parts known as the " mushroom" which 

 elevates itself into the atmosphere, and produces reproductive 

 bodies like seeds called spores; and we also have underground 

 white threads starting out from the base of the mushroom which 

 at their terminus bear buds which next year become mushrooms, 

 as the swollen ends or tubers of the potato produce plants. The 

 observations, which he supposed new, referred to the distance 

 which the spawn-threads traversed in one season, and the regular 

 manner in which the mushrooms appeared from the parent of the 

 past year. 



In the autumn of 1871, passing over a part of his farm where 

 he had seen no mushrooms in previous years, he found two soli- 

 tary specimens several yards apart. This season, where these two 

 were gathered last year, there were two. exact circles of several 

 dozens of mushrooms, the circles about nine feet in diameter. 

 The mushrooms were wholly confined to a belt of about six inches 

 on the margin of this circle. The diameters in both instances 

 being the same, led to the fair inference that about four feet is 

 the distance travelled in one season by the spawn of the mush- 

 room. Of course, next year, when the spawn starts from the bases 

 of the mushrooms now in the circle, some will go back over the 

 distance traversed this year, and the appearance of circles will be 

 broken up, and it was owing to the fact of only two appearing in 

 this way, that the radiating character could be observed. 



In England there are fungi which are known to radiate then- 

 threads from a common centre in this way. These destroy the 

 vegetation which they come in contact with on their route, and 

 make brown circular spots known to the common people as Fairy 

 rings. The grass and vegetation inclosed in the mushroom rings 

 were not destroyed as in those instances, but exhibited a slight 

 bluish tint which that beyond the circle did not, which tint was 

 a sign of slight injury. The facts that the mycelium radiated in 

 so exact a circle, terminating in a bud which produced the mush- 

 room ; and that this radiation covered a circle nine feet in diame- 

 ter, he thought novel facts worth recordino-. 



August 20. 

 Mr. Tryon in the chair 

 Ten members present. 



August 27. 



The President, Dr. Ruschenberger, in the chair. 



Eleven members present. 



On favorable report of the committee, the following paper was 

 ordered to be published : 



