MUSHROOM GROWING 



but from the standpoint of development 

 and physiology, our data are scattering. 



Species, Employing the term in its nar- 

 rower sense, the several species of truffles 

 are all members of the genus Tuber, w^hich 

 in turn, is the dominant genus in the family 

 TuberacecB. The genus Tuber embraces 

 more than fifty known species. The more 

 important of the edible species, or forms, are 

 six, and these latter may be divided into two 

 groups: — (i) Those in which the fruit 

 body is dark brown or black, and the sur- 

 face covered with wart-like structures; and 

 (2) those in which the fruit body is yellow 

 or yellowish brown, and the surface usually 

 smooth. The black truffles give us the most 

 highly prized and abundant edible species, 

 such as Tuber cestivum Vittad., T. mesen- 

 tericum Vittad., T. uncinatum Chatin, T. 

 brumale Vittad., T, melanosporum Vittad.; 

 some might also include T. gulonum Cda., 

 T. montanus Chatin, etc. Among those of 

 the lighter colored group the only really im- 

 portant species is T. magnatum Pico, al- 



192 



