142 Cincinnati Society of Natural History. 



The Gastromycetes are fungi mostly of large size, growing 

 usually upon the ground sometimes just beneath its surface, rarely 

 upon wood. Their mycelium often exhibits an extensive develop- 

 ment, the hyphae uniting together into strands which in form 

 branching and mode of growth in the substratum simulate the roots 

 of higher plants. The peridium is a closed wall of dense texture 

 mostly spherical in form and often of considerable thickness ; it 

 may consist of a single coat of uniform texture or more commonly 

 it is separable into two distinct layers the inner and the outer 

 peridium. In many cases the pcndium is extensively and pecu- 

 liarly differentiated partly into persistent and partly into temporary 

 parts; it is a general occurrence in the course of this differentiation 

 that the peridium becomes strongly thickened at the base ; the 

 thickened portion either projects outward forming a stout support to 

 the gleba or it projects inward forming a cushion of moderate thick- 

 ness or an elongated vertical central column. The chambers or 

 the cells of the gleba generally are in countless numbers seldom few 

 and definite ; they are narrow irregularly curved and branched 

 cavities scarcely large enough to be distinguished by the naked eye. 

 In some cases the gleba retains this primary structure throughout 

 its entire existence, subject only to the changes in size of all its 

 parts caused by growth and maturity; in other cases the cells of 



one on the genus Lycoperdon, by Chas. M. Peck, the other on the genus 

 Geaster, by myself. 



It is true, these are the large genera and contain half the species of the 

 whole cla^s. Tie genera of the different Orders stand about as follows: 



Order. Genera. 



Phalloidese, ........ 5 



Lycoperdaceae, . . . . . . 10 



Sclerodermaceae, ....... 7 



Hymenogastracege, ...... 6 



Nidulariicese, ....... 5 



Gastromycetes, • • • ■ ZZ 



Our own region, the Miami Valley, i'i remarkably prolific of puff-balls, and 

 I have probably seen more of these things living and growing than any 

 other person in the wi rid. I have specimens of nearly every species that 

 have been found in the United States, and among them quite a number that. 

 have not yet been noticed in print. 



Very truly, yours, 



A. P. Morgan. 



