HOTSON. — CULTURE STUDIES OF FUNGI. 249 



in size, the measurements of Melanospora papillata and M. cervicula 

 averaging 10 X 25 /u while those of M. anomala are slightly larger, 

 12 X 28 ix. These variations, however, are so small that they could 

 not alone be considered as specific. The size anil shape of the asco- 

 pores also correspond quite closely with those of Melanospora Gibel- 

 liana and Sphaeroderma bulbilliferum. At maturity the ascospores 

 appear as an irregular black mass in the center of the perithecium. As 

 in all the species of Melanospora the asci are very evanescent. The 

 walls become gelatinous and swell by the absorption of water, which 

 increases the volume to such an extent that the mucilaginous mass 

 protrudes from the ostiole, carrying out with it the embedded spores. 

 If the atmosphere is somewhat humid, this mass of spores, as they 

 are forced out, aggregate in a spherical mass at the mouth of the 

 ostiole; but if the air is dry as they are pushed out, they adhere to- 

 gether into a long, twisted, tendril-like filament, something like 

 the paint as it is squeezed out of an artist's paint-tube. These eirrose 

 structures may measure from 10-18 mm. in length, and twist up into 

 a variety of shapes. The spores not infrequently germinate while 

 still in the cirrus, giving it a white appearance. 



Microtome sections show no paraphyses between the asci, but from 

 the walls there grow out more or less conspicuously into the cavity 

 above the asci, numerous hyphal branches, as paraphyses, which con- 

 verge radially and extend upwards towards the ostiole. These prob- 

 ably aid in the formation of the neck when it is present. 



In general the culture methods used were the same for all. Gross 

 cultures of the various substrata were made in crystallizing dishes 

 which were half-filled with sphagnum and covered with white filter 

 paper, on which the substratum was placed. The whole was then well 

 supplied with water and covered with a piece of plain glass and set 

 in a place in the laboratory where it would be protected from the 

 direct sunlight When bulbils were observed, individual ones were 

 carefully picked out under a dissecting microscope and cultures made 

 from them, until a pure culture was obtained. These were grown on 

 various kinds of media until perithecia with the characteristic long 

 cirri of ascospores, were obtained. Transfers of the ascospores were 

 then made by touching one of the aerial cirri with a piece of nutrient 

 agar on the end of a sterilized needle. In all cases pure cultures of 

 ascopores obtained in this way produced bulbils. 



The germination of tin- ascopores was followed in Van Tieghem cells 

 until bulbils were again produced on the mycelium, thus demonstrat- 

 ing the connection between the ascospore and the bulbil. 



