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are chiefly from among those which grow upon decaying 

 organic refuse. One interesting parasite exhibited is a 

 fungus parasitic upon another fungus, which, in turn, is a 

 parasite on the leaves of the common lilac. Another fungus 

 shown lives chiefly within the cells of the underground parts 

 of one of the orchids, yet it can scarcely be called a parasite, 

 inasmuch as its presence in the tissues of the orchid is bene- 

 ficial to the orchid as well as to itself. Of the fungi which 

 live upon decaying refuse matter, Ascobolus is one of the 

 more interesting among those selected for exhibition. In 

 this, the spores, or propagating cells, are borne in groups of 

 eight within transparent ellipsoidal sacs, and at maturity these 

 sacs, each enclosing eight spores, are ejected with consider- 

 able force. Under two microscopes are shown sections of 

 lichens, illustrating their mode of reproduction and the fact 

 that a lichen consists essentially of two organisms, a fungus 

 and an alga, intimately associated and constituting what for 

 many purposes may be looked upon as a single organism. 



Then follow specimens of the liverworts or scale-mosses, 

 plants in which the differentiation of the vegetative body 

 into stem and leaves becomes first clearly evident. One of 

 these, a Frullania^ has a part of each leaf peculiarly modi- 

 fied so as to form a reservoir for water. By aid of this 

 device, the frullanias and their allies are able to thrive in 

 drier situations than are in favor with most of the order to 

 which they belong. Preparations are exhibited showing also 

 the vegetative structure and methods of reproduction of the 

 true mosses. Especially interesting is the " peristome " of 

 one of the mosses, which is a fringe of peculiar appendages 

 surrounding the mouth of the little urn in which the minute 

 dust-like spores are borne. These appendages move about 

 as a result of changing conditions of moisture and these 

 mechanical movements assist in scattering the spores. A 

 somewhat analogous device is found in connection with the 

 spores of the equisetums or horse-tails, though the appendages 

 in this case are attached to the spores. Following the slide 

 illustrating this feature of the horse-tails is one showing the 



