SPOROBOLOMYCES AND BULLERA 



301 



culture with a culture of Sporobolomyces in a characteristic pattern 

 and incubates the plate, there is formed a faint duplicate of the 

 colony pattern upon the lid of the dish (Fig. 121). These mirror 

 colonies are formed by a deposition of the spores which are forcibly 

 discharged from the surface of the colony. 



Microscopic examination of a young colony shows only the pres- 

 ence of ordinary oval, budding yeast cells. But later, as spores 

 develop (manifested by the occurrence of a powdery coat on the 

 surface of the colony), many cells will be found with fine pointed 

 projections exactly like the sterig- 

 mata which are found on the basidia 

 of a mushroom. On these there 

 appear typical kidney-shaped cells 

 which reproduce very closely the 

 form of the basidiospores of some 

 mushrooms. The discharge of 

 these spores has. been observed by 

 Kluyver and van Niel and by Buller 

 who report a mechanism which 

 exactly parallels that in the Basidio- 

 mycetes. The discharge of the 

 spore is accompanied by the devel- 

 opment of a drop of water at the 

 point of attachment of the spore 

 with its sterigma. When this drop 

 has reached a certain size, the spore is suddenly and forcibly pro- 

 pelled into the air. Buller has observed the successive production 

 and discharge of as many' as three spores from one sterigma and 

 assumes that four may be formed. Occasionally more than one 

 sterigma may form from a single cell. 



The Sporobolomycetaceae have been considered as imperfect stages 

 of species of the Tremallales ^^ of the Heterobasidiomycetes (see 

 page 33). In this order, the basidiospores reproduce by budding and 

 repetition, this one stage of the Tremallales closely resembling the 

 whole life cycle of the Sporobolomycetaceae. We have seen how the 

 basidiospores (sporidia) of the smuts also proliferate. 



Two species of Bullera and seven of Sporobolomyces are recognized 

 by Derx and several additional species were described by Ciferri and 

 Verona. These genera are not very common but may be isolated 

 from straw or leaves. We have on two occasions isolated Sporo- 

 bolomvces from bananas. 



Fig. 122. Sporobolomyces sabnoni- 



color. Basidiospores attached to 



sterigmata are marked s. 



