THE INAEQUI-HYMENIIFERAE 129 



structure and function have been brought to hght. In 1910, I 

 pubhshed an account of Coprinus atramentarius in which were 

 described the function and fate of the large cystidia which occur in 

 this species.^ It was shown that the mechanism for the production 

 and liberation of spores in C. atramentarius is essentially the same 

 as in C. comatus, but that the two species differ in the manner in 

 which adjacent gills are prevented from coming into contact during 

 the ripening and discharge of the spores. In Coprinus comatus the 

 surfaces of adjacent gills are kept apart owing to the fact that the 

 gill-edges are swollen so that each forms a flange, whilst in C. atra- 

 mentarius the surfaces are kept apart by the presence of numerous 

 cystidia which stretch across the interlamellar spaces and act as 

 stays or distance-pieces. In Coprinus atramentarius the gills are 

 very broad and yet extremely thin : consequently they are lacking 

 in rigidity. The presence of the cystidia is absolutely necessary in 

 this species to prevent adjacent gills from touching one another, 

 and is therefore an essential factor in the successful production and 

 liberation of the spores. I called attention to the fact that the 

 gills of Coprinus atramentarius are parallel-sided and stated the 

 important conclusion that, in the Coprini, the ripening and dis- 

 charge of the spores from below upwards on each gill, and the gradual 

 autodigestion of the spore-free portions of the gills from below 

 upwards, are to be regarded as adajDtations which permit of success- 

 ful spore-liberation from parallel-sided gills. 



In a further paper, in 1912, I pointed out that in the Coprini the 

 gills, unlike those of most Agaricineae {PsaUiota campestris, etc.), 

 do not react to the stimulus of gravity, i.e. they are ageotrojnc, and 

 also that the basidia are dimorphic.'^ The basidia in the hymenium 

 of most Coprini {Coprinus comatus, C. atramentarius, C. stercorarius, 

 C. ephemerus, etc.) are of two kinds, long and short. The long and 

 short basidia are interspersed among one another and among the 

 paraphyses, so as to form a beautiful mosaic-work. It was shown 



1 A. H. R. Buller, " The Function and Pate of the Cystidia of Coprinus atra- 

 mentarius together with some General Remarks on Coprinus Fruit-bodies," Annals 

 oj Botany, vol. xxiv, 1910, pp. 613-629. 



2 A. H. R. Buller, "The Production and Liberation of Spores in the Genus 

 Coprinus," Transactions of the British Mycological Society for 1911, vol. iii, 1912, 

 pp. 348-350. 



VOL. III. ^ 



