VOLUME XLVI 



NUMBER 6 



Botanical Gazette 



DECEMBER 1908 



LIBRARY 

 NEW VORK 

 BOTANICAL 

 CIARDL 



BRYOLOGICAL PAPERS 



II. THE ORIGIN OF THE CUPULE OF MARCHANTIA 



CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 120 



Charles R. Barnes and W. J. G. Land 



(with fourteen figures) 



The study of the cupule of Marchantia has evidently been con- 

 fined to the later stages of its development, and especially to the 

 origin of the gemmae and the order of cell division in them. Nowhere 

 have we been able to find any account of the origin of the cupule, 

 and the earlier stages of its development seem to have escaped obser- 

 vation. Its homology with other structures in the upper part of the 

 thallus has apparently been a matter of speculation rather than of 

 investigation. Thus, Campbell casually remarks 1 that the gemma 

 cup is apparently a specially developed air chamber, but. gives no 

 details and adduces no evidence therefor. 



Although Marchantia has been much investigated and indeed has 

 been long a favorite subject for instruction in laboratories, Kny 

 seems to have been the first to examine any of the early stages of 

 development of the cupule itself. This he did for the purpose of 

 illustrating the development of Marchantia on his charts and describ- 

 ing the same in the accompanying text. 2 But he does not show or 

 describe the origin of the cupule; the earliest stage referred to corre- 

 sponds roughly to our fig. 10, when it has become a rather deep pit. 



Our studies upon the origin of the air chambers in Marchantiales 3 

 suggested to us an inquiry into the origin of the cupule, to determine 



1 Campbell, D. H., Mosses and ferns, 2d ed. 44. 1905. 



2 Kny, L., Wandtafeln. Ser. Ill, pi. 84, text p. 366. 



3 Barnes and Land, The origin of air chambers. Bot. Gazette 44:197-213. 

 1907. 



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