272 



OUTLINES 01- PLANT LIFE. 



it of neighboring parts, increasing until the spore case rup- 

 tures suddenly and the spores are shot out like projectiles. 

 In some plants the whole spore case is thrown off in this 

 fashion, often to the distance of a meter or more (fig. 234). 

 The fungus which attacks and kills house flies in summer 

 casts off the single spore from the end 

 of the stalk carrying it by the bursting 

 of the end of this stalk through ex- 

 cessive turgor (fig. 235). With the 

 spore goes the contents of the stalk, 

 so that it is surrounded by a mass 

 of mucilage, thus enabling it to adhere 

 to any object which it strikes. 

 Filaments carrying the 

 spores often twist upon drying 

 and thus jerk off the spores 

 as they suddenly slip past 

 some obstruction. When 

 spores are produced in chains, 

 there are devices to separate 

 them at maturity so that the 

 lightest breath may carry 

 them away. The teeth around 



B A 



Fig. 235, — 4, a fly killed by the fly fungus 

 {Eiii/>iisa Miiscii'), stuck to wall by hyphs 

 and surrounded by a halo of the spores. 

 Two-thirds natural size. B, hyph^ pro- 

 jecling into the air from the body of the the mOUth of the Capsule of 

 tiy, rrom whose tips spores are being shot ^ 



off Several are shown in various stages moSSeS Serve tO distribute the 

 or development, i he turgor of the en- 

 larged end of hyplia finally rupture^s^ t^i| SpOrCS at OppOrtUllC intervals, 



of having them 



attachment of the spore and it is sh^ 



surrounded by the mucilaginous contents instead 



which cause it to adhere to any object 



struck. Magnified 200 diam c a spore emptied out all at oucc. (See 



enveloped in mucilage. Magnified 420 ^ V 



diam.-After Kemer. flg^ 46, A.) In SOme CaSCS 



the teeth, by their form and hygroscopic curvatures, serve to 

 sling out the spores to a short distance. In many ferns the 

 spore cases are furnished with a spring-like structure (the 

 annuhis) along the greater part of the edge, which tends to 

 straighten itselt upon drying, thus rupturing the spore case. 



