6i6 
Buller .— The Function and Fate of the 
these quotations it is evident that Brefeld regarded his suggestion as tenta¬ 
tive, and that he did not feel justified in laying much emphasis upon it. 
Notwithstanding the fullness of his illustrations, he did not show cystidia 
stretching between the gills; nor did he say anything about their ultimate 
fate. 
In the present paper I hope to prove that the cystidia of Coprinus 
atramentarius do actually serve the purpose suggested by Brefeld. I shall 
further endeavour to explain why the gills should be kept a certain distance 
apart, and finally, how the cystidia are got rid of, when by their presence 
they would constitute a hindrance to the escape of the spores from between 
the gills. A study of the comparative anatomy of C. atramentarius and 
C. contains will enable us to understand why cystidia should be present on 
the general gill-surfaces of the former species and absent from those 
situations in the latter. 
In a recent publication I 1 have given a somewhat detailed account 
of the beautiful mechanism of the fruit-body of Coprinus comatus . It was 
shown that the spores ripen on the gills from below upwards, and that there 
is a zone of spore-discharge that passes from the bottom to the top of each 
gill in the course of about forty-eight hours. It was further shown that 
c deliquescence ’ is a process of auto-digestion that serves to remove those 
parts of the gills which have already shed their spores and which, if they 
continued in existence, would hinder the fall of the remaining spores. 
I stated that the arrangements for spore-liberation in Comatus atramentarius 
were essentially the same as those in Coprinus comatus . 2 Whilst this 
statement is true, we shall see that the presence of the cystidia on the 
general surfaces of the gills in the former species and their absence in the 
latter are associated with some very interesting differences in detail in 
the respective fruit-body mechanisms. In order to explain the function of 
the cystidia of Coprinus atramentarius , it will be necessary to describe the 
general structure of the fruit-body and the mode of spore-liberation. 
II. Investigations on Coprinus atramentarius. 
i 
Coprimes atramentarius is one of the largest and commonest species of 
its genus. It is widely distributed over the earth’s surface, and has been 
found in Europe, North America, Australia, and Kerguelen. Island. 3 The 
genus Coprinus , according to Hennings, 4 contains about 175 species. 
Whilst most of them grow on dung or dunged ground, a few occur on dead 
stems or wood. Coprimes atramentarius belongs to the minority, and, 
1 A. PI. R. Buller, Researches on Fungi, London, 1909, part i, chap. xix. The Coprinus Type 
of Fruit-body, pp. 196-215. 2 Ibid., p. 208. 
3 G. Massee, A Revision of the genus Coprinus. Ann. of Bot., vol. x, 1896, p. 143. 
4 P. Hennings, in Engler u. Prantl, Die nat. Pflanzenfamilien, Teil 1, Abteil. 1**, p. 205. 
