Vegetative reproduction and aposporous growths from the young 
sporophyte of Polypodium irioides 
W. N. STEIL 
(WITH THREE TEXT FIGURES) 
From an old culture of the prothallia of Polypodium irioides 
Poir. made March 21, 1916, the largest gametophytes, including a 
number bearing sporophytes, were on several occasions removed 
for class use. In the autumn of 1918, when regeneration from the 
sporophyte was first observed, only three sporophytes remained 
in the culture. 
The largest and most vigorous bore six leaves and by March 
4, 1919, had produced nine leaves. The largest leaf of this 
sporophyte was about 5 cm. in length and 5 mm. in width. 
From one of the smaller leaves of the sporophyte regeneration 
occurred. This leaf was only 1 cm. in length and 3 mm. in width. 
There was a well-developed vein in the 
leaf and the epidermal cells, including 
the guard cells, were of the usual type. 
It was impossible to determine whether 
the leaf was the primary one, since the 
juvenile leaves of this fern resemble 
closely one another and also the leaves 
of the mature sporophyte. Three of the 
sporophytic growths produced by the 
leaf originated along the margin (Fic. 1, 
b,c, and f), one from the lower surface 
(d), and one from the upper surface (c). 
From two portions of the leaf were oe. K Galea oouag 
developed complete sporophytes, that is, sporophyte of Polypodium 
sporophytes with both leaves and roots iris Sagem eee 
(Fic.1,bandc). Theother outgrowths —o. ae sem r ree . 
consisted of one or more leaves, and one 
bore in addition to two leaves numerous rhizoid-like hairs from 
the point of origin of the leaves (s). These were extremely long, 
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