

. 



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DIFFEREXTIATIOX OF SPOROCARPS IN AZOLLA 



CONTRIBUTIONS FROM THE HULL BOT.\NICAL LABORATORY 105 



Waxda il. Pfeiffer 



GRirriTH 

 pi nil at a, ( 



(with PLATES XXXI AND XXXH) 



the work on Azolla up to 1844 



Working on Azolla 



sporocarps. The eariicst stage described showed two sporocarps 

 within a hoodh'ke involucre. Each 



sporocarp 



shaped integument and a cellular body, the ^'nucleus,"^ which was 

 surrounded by the "integument"* and projected from it. Later the 

 "nucleus" elongated and the "integument" grew out so rapidly as 

 finally to inclose it. At a still later stage, simple capitate "filaments"^ 



developed abo 



Up to this 



point, the development in the two organs had been similar. After 

 this, there might be a development of either the "nucleus" or the 

 cellular projections about its base, but in no case did both continue 

 growth. In cases where the further growth was in the "nucleus," 

 Griffith describes it as developing into the "so-called male organ" 

 of former writers. This organ consisted of an egg-shaped body, 

 bearing a calyptra and containing a large yellow sac capped by a 



body. The first 



*x^ 



was a granular condensation of the materials of the "nucleus." When, 

 on the other hand, only the "so-called female organs" developed, 

 the first step was the appearance of a granular mass in the swollen 

 tip of each of the "filaments," which had appeared in centrifugal 

 order about the base of the "nucleus." 



Nearly thirty years later (1873), Strasburger (2) wrote Ueber 



A zolla 



sporocarp 



said little about their development. He found in the early stages of 



^ From GRrPFiTH's figures it is evident that this "nucleus'* is the megasporangium. 

 * The ''integument" is the sporocarp wall. 



^ These "filaments" are evidently the young micrt 

 the massive stalk of the megasporangium. 



445] 



arise 



[Botanical Gazette, vol. 44 



