Abnormal elaters of Porella platyphylla 
FL M. ANDREWS 
(WITH PLATE 3) 
In 1908 the writer* described and illustrated an archegonium 
of Porella platyphylla having two egg-cells, two ventral canal 
cells, and two rows of canal cells, therefore forming two complete 
axial rows instead of the usual one row. The elaters also were 
abnormal in that they were branched, in one case slightly and 
in another to a considerable extent. 
In 1914 Manningt reported another case of an archegonium 
of Porella platyphylla, similar to the one above referred to. These 
abnormal archegonia coincide with the idea of Davis} concerning 
the origin of the archegonium. In Mnium also Coker§ found 
an archegonium containing two egg-cells, which, however, were 
superposed. More than one row of canal cells have been noted 
in the archegonium of Mniwm cuspidatum by Holferty;|| Pace { 
has observed two adjacent archegonia in the prothallia of a 
fern with no wall between the egg-cells; and Lyon** has recorded 
other peculiarities in the archegonia of certain pteridophytes. 
The present account deals with some unusual forms of the 
elaters in Porella platyphylla.tt While studying some material 
of this plant which was collected near Bloomington, Indiana, 
the writer observed that a few of the capsules contained a number 
of abnormal elaters, although nearly all of those examined were 
of the usual shape. Some of the abnormal elaters were kept 
for a time on the slide and not mounted permanently, so as to 
* An abnormal Porella platyphylla. Bot. Gaz. 45: 340. f. 1-3. ‘ 
t Life history of Porella platyphylla. Bot. Gaz. 57: 320-323. pl. 15, 16. 
I9I4. 
t The origin of the archegonium. Ann. Bot. 17: 477-492. J. 22, 22, 1903. 
§ On the occurrence of two egg cells in the archegonium of Mnium. Bot. 
Gas. 35:..137. 7. 2, 2904. 
|| The archegonium of Mnium cuspidatum. Bot. Gaz. 37: 106-126. pl. 5, 
6. 1904. 
{ Bot. Gaz. 50: 52. I9gI0. 
** Bot. Gaz. 37: 282-285. 1904. : 
+t For a consideration of Porella platyphylla and P. platyphylloidea see 
Miiller in Rabenhorst’s Kryptogamen-Flora 62: 573, 581. 1915. Also Evans, 
Rhodora 18: 74-85; 103-119. 1916. ° 
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