INTRODUCTION TO CRYPTOGAMIC BOTANY. 347 



acquire a rounder form, tUl at length their vertical tendency is 

 so strong that the volva is ruptured, a circumstance which could 

 only be effected by the exercise of immense force. Sometimes, 

 however, instead of a stem, the receptacle of the hymenium 

 has a similar structure, and has the same effect in rupturing 

 the volva. The stem, moreover, is fixed at the base by a very 

 small point, and could not remain erect without some sustaining 

 force. This is supplied by the lobes of the volva, which do 

 not turn back, like those of the peridium of a Geaster, but 

 contract on the stem, thereby preventing its fall. The hyme- 

 nial mass assumes several forms. Sometimes it is simply 

 clavate, being perforate or imperforate at the apex ; sometimes 

 it is pitted like the pileus of a Morchella ; sometimes the 

 border is free, as in a Verpa, and beneath this are one or more 

 frill-hke appendages, which are either simply membranous 

 or most beautifully reticulated, so as to hang down hke an 

 umbrella beneath the pileus. The pileus may be either entire 

 or fissured at the tops, with the tips of the lobes adherent, as in 

 Lysurus, or beautifully stellate, as in Aseroe. The rays are 

 occasionally extremely numerous, as in CalatJiiscus. In those 

 cases where there is no stem, the receptacle forms a more 

 or less perfect network, sometimes reduced to three or four 

 meshes only. The colours are often extremely beautiful, but 

 these are mostly compensated by a most odious smell. Even, 

 however, in those cases where it is most loathsome, and where 

 the odour pervades the atmosphere for some distance, it is 

 asserted that this is sometimes so modified as to become even 

 agreeable. Notwithstanding such discouragement, the gelati- 

 nous volva of more than one species of Ileodidyon is eaten by 

 the New Zealanders under the name of Thunder dirt, as is also 

 that of Phallus Mohusin in China, while the head is supposed 

 to be an effectual cure for ulcers. No other use seems to be 

 made of these productions ; but the dripping hymenium affords 

 a welcome food to multitudes of flies. 



376. They are essentially plants of warm countries, though 

 the most common species. Phallus hnpudicus and caninus, 

 ascend to high northern latitudes. The greater number of 

 species, however, are found only in tropical or sub-tropical 



