6. PETCH : 



during the niglit, and some of them were i)hotographed on 

 the following morning. The time of expansion appears to be 

 short. All the expanded specimens were removed from one 

 pot at 7.45 A.M.. and it was tlien noted tliat some of the eggs 

 were ruptured at the apex, and that tlie peculiar crown of the 

 pileuH was just protruding. Arguing from the case of Miithius 

 Flfijicheri, it was expected that these would remain in that 

 condition at least luitil tlie next morning ; but by 8.45 a.m. 

 they were all fully ex})andcd : a favourable ojiporlunity of 

 observing the expansion was thus unfortunately lost. 



The specimens varied in height from 3 • 5 cms. to 14 cms. The 

 smallest specimen was 3-5 cms. higli, witli a stalk 4 )nm8. in 

 diameter and a jnleus 1"2 cm. long. The largest was 14 cms. 

 high, with a s^k 1 cm. in diameter and a pileus 2-6 cms. long. 



The wall of the stalk consists of a single layer of chambers, 

 varying much in size in different specimens. Tlie chambers 

 are not arranged in definite lines. When the chambers are 

 small the stalk sf unds erect ; but as a rule it is curved. This 

 curvature is the result of the extreme weakne.ss of the stalk, 

 jiartly becauw* the chambers are large, but (chiefly because 

 most of them are perforated on the exterior. In some cases 

 the chambers form merely a network of ridges on an inner 

 membrane. Tlie stalk therefore soon collapses under the 

 weight of the })ileus. as is shown on PI. I., B ; these specimens 

 were developed inider a bell glass and were photographed in 

 the early morning soon after expansion, but they began to 

 <'ollap8e as soon as the bell glass was removed. 



In the smaller specimens the stalk is practically of the sanie 

 diameter throughout, but in the larger it diminishes towards 

 the apex. The colour of the stalk in all my specimens is 

 while, while that of the jtileus is pale yellow. 



'I'he jjileus is somcnvhatr ovoid ; it swells f)ut regularly from 

 till' a])ex, l)ut contracts again below, so that the lower edge is 

 sometimes in contact with the stalk. It is united to the stalk 

 only at the aj)ex. It is covered by a network of fairly deep 

 ridges with corresponding grooves on the under surface. The 

 ftpex is perforated and sj)reads out, in typical specimens, in a 

 horizontal diw. The inner layer of the wall of the stalk is 

 thickened at the apex and bonds out horizontally, the cross 



