OMPHALIA FLAVIDA 417 



body, whatever its origin, cannot now be called a sporophore, for it 

 produces no basidiospores or conidia ; and to call it an aborted 

 sporophore is to neglect the fact that it is an active organ with a 

 definite reproductive function and interesting structural characters 

 of its own. A stilbum-hody is in reality a gemmifer, and in what 

 follows it will be thus designated. 



The gemmifer of Omphalia fiavida consists of two parts : ( 1 ) the 

 stalk which we may now call the pedicel, and (2) the head which is 

 in reality a gemma. 



Under natural conditions, according to Maublanc and Rangel,^ 

 the gemmae (their s^i76ww-heads) are the actual means by which 

 Omphalia flavida is disseminated and reproduced, for the perfect 

 sporophores were seen by them only in artificial cultures in which 

 the atmosphere was saturated with water vapour. While it is true 

 that the leaf-spots on attacked leaves of Coffee, etc., give rise only 

 to gemmifers, it is possible, as Maublanc and Rangel point out, 

 that the perfect fruit-bodies are sometimes developed on fallen 

 leaves in very wet situations on the ground, although, so far, 

 apparently no one has ever seen them there. It therefore seems 

 that, in Omphalia flavida, reproduction by gemmae has largely or 

 wholly taken the place of reproduction by basidiospores. This 

 suppression and replacement of basidiospores finds analogies else- 

 where. Thus chlamydospores have completely or almost completely 

 taken the place of basidiospores in Nyctalis 2 and in Ptychogaster.' 



That the gemmifers of Omphalia flavida are well suited to act 

 as reproductive organs is shown by the following considerations. 

 (1) The gemmifers are produced in considerable numbers. Each 

 spot on a Coffee leaf in an entire season may produce 20-50 gemmi- 

 fers ; but as many as 70 have been observed on a leaf-spot 7 mm. in 

 diameter .4 (2) A gemma is easily detached from its pedicel by 

 wind, rain, or other mechanical means. (3) The gemmae are very 

 small, each being about one-third of a millimeter in diameter. 

 Owing to their small .size they are readily transported by mechanical 



1 A. Maublanc et E. Rangel, loc. cit., p. 45. 



2 These Researches, Vol. Ill, 1924, pp. 447-448, 463. 



3 O. Brefeld, Untersuchungen iiber Pilze, Heft VIII, 1889, pp. 114-142. 

 * G. L. Fawcett, loc. cit., p. 11. 



VOL. VI. 2 E 



