386 BOTANICAL GAZETTE. [May 
Kasuyap (7, 8), however, describes for E. debile much the condition 
found in these gametophytes of E. Jaevigatum, except that he 
rarely found antheridia occurring on gametophytes bearing sporo- 
phytes. Evidently the gametophytes examined by BUCHTIEN and 
Kasnyap very closely resembled those of E. laevigatum under 
consideration. 
Sex organs 
Archegonia (figs. 8, 13, 14) were present in all stages of develop- 
ment and agree closely with those described by BucHTtEN (1), 
SADEBECK (9), CAMPBELL(2), HOFMEISTER (5), GOEBEL(3), and others. 
The only point of disagreement as to the archegonia of Equisetum 
appears in connection with the neck canal cells. In E. laevigatum 
the condition does not seem uniform. In many cases there 1s 
evidently only one neck canal cell. In a few archegonia, however, 
the vertical division had occurred and given rise to the two charac- 
teristic boot-shaped cells. The archegonial initial appears at any 
point on the peripheral meristem, not always on the under side, 
but in all cases the archegonia are pushed to the upper surface by 
the growth of the meristem below (figs. 8, 14). Branches usually 
develop at each side of an archegonium (fig. 14), so that when 
mature it lies between two branches. 
Antheridia in large numbers also were present in all stages. 
They showed but one type of development, that characteristic 
of eusporangiate ferns. In the examination of more than fifty 
gametophytes in paraffin sections, only half a dozen antheridia 
were found on the upright branches. These (fig. 18), however, were 
not at the tip ot the branch, but showed definitely the same develop- 
ment as others, which were developed in the massive meristem at 
the periphery of the thallus (figs. 9, 12, 13, 15-17). It is interesting 
to note that BucuTIEN (1) considers even the antheridia developing 
at the tips of branches to be of the eusporangiate type. He says It 
seems that the antheridia at the tip of a filament and those in @ 
cell mass develop differently, but it is only an apparent difference. 
In a filament there are no suitable conditions for antheridial 
development, so three vertical walls cut out surrounding cells which 
take the place of a thallus mass. Then the real antheridial initial 
is not the end cell of the filament, but the tetrahedal cell surrounded 
