PUFF-BALL FUNGI— GAS TROMYCETES 153 



liquefying hymenium is visited by large numbers of flies, 

 which sometimes almost cover it, and suck up the fluid mass 

 with great avidity during hot sunny days ; but when the 

 weather is cloudy or cold, fewer flies are to be seen." 



Examinations were made of flies taken from the deli- 

 quescing gleba, and thousands of spores were found adhering 

 to the feet and proboscis. The flies placed in confinement 

 showed that their excrements were almost exclusively com- 

 posed of spores. To determine if the excrementary spores 

 retained their vitality they were placed in tubes on sterilised 

 earth. The tubes were then closed with cotton -wool and 

 buried with the contained spores, and different substances 

 with them. In about two months the spores had germinated, 

 and in some produced a plentiful mycelium. Hence it is 

 clear that the spores after passing through the stomachs of 

 insects do not lose their power of germination. 



This family is remarkable for the prevalence of a bright 

 red colour near the hymenium, and also for the peculiarity of 

 many of the forms. In Dictyophora, Ithyphallus, and Mutinus 

 the form is columnar and phalloid ; in Clathrus and Colus it 

 is clathrate. In Calathiscus and Aseroe the disc is stellate, 

 and in Kalchlrennera it is coralloid. The spores in all the 

 species are very profuse and minute, generally involved in 

 mucus. 



In the family of Nidulariaceae we meet with other 

 peculiarities, and of these the common species of Cyathus or 

 Crucibulum, called the " bird's-nest Fungus," may be taken as the 

 type (Fig. 64). There are altogether only about sixty described 

 species, and the family, under some of its forms, is pretty 

 widely distributed. When mature the Fungus is not more/ 

 than from one to two centimetres high, and resembles in form 

 little inverted bells, at first covered across the mouth with a 

 white membrane or operculum, which when ruptured exposes 

 a number of lentil-shaped bodies, packed like eggs in a little 

 bird's-nest. These are the peridioles, each of which is 

 attached to the inner surface of the cup by a long elastic 

 cord, proceeding from the under face of the sporangiole. 

 Each of these sporangioles, when cut in section, reveals a 

 central cavity, into which the basidia project, with their 



