28 BOTANICAL GAZETTE [JANUARY 
the cycads rather than with the ferns. Without hoping to 
settle this question at the present time, it may be profitable to 
consider some of the arguments advanced by Mr. Seward in 
the light of evidence obtained from an examination of material 
derived from existing species, as also from the Topeka specimen 
itself. 
VASCULAR sisi. he examination of both cycadaceous 
plants and Angzopterts evecta affords but little evidence contrary 
to the view urged by Mr. Seward. The evidence obtained shows, 
as he contends, that the position of the protoxylem in these 
plants is certainly an argument in favor of the cycadaceous 
character of Myeloxylon. On the other hand, the collateral 
character of the vascular bundles in the latter cannot be taken 
as final evidence of affinity either with the ferns or with the 
cycads, as Mr. Seward himself points out. Although the longi- 
tudinal sections of the Topeka specimens have given far from 
satisfactory results, the evidence to be derived from them indi- 
cates a much closer resemblance to Angiopteris than to any of 
the cycads I have been able to study. 
SECRETORY ORGANS.—In the Cycadacez, as represented by 
Cycas revoluta, Zamia integrifolia, and Dioon edule, the secretory 
organs appear to be all of one kind as represented by mucilage 
canals. These structures are distributed throughout the funda- 
mental tissue and are represented by broad canals which are 
ease limited by tangentially elongated parenchyma cells. 
hese latter, therefore, differ somewhat conspicuously from the 
cells of the surrounding tissue, as already shown by Mr. Sew- 
ard.7 So far as appears | from the species above indicated, how- 
ever, these canals are always lined with a layer of very thin- _ 
walled epithelium cells, which become ruptured with age and, 
shrinking back upon the main wall of the canal, give it a thick- 
ened and very ragged appearance. ee 
In Angiopteris evecta there are three distinct ‘ands of secre- 
oy organd (ae tannin oni dee resin eae “and ee tte os 
