June, 1921] 
CAMPBELL THE EUSPORANGIATE FERNS 
as it does in Ophioglossum Mohiccanum and the Marattiales, and the foot 
thus is practically obliterated, instead of forming a large part of the embryo 
as it does in B. Virginianum. In the latter, as we have seen, the primary 
root and the cotyledon make a sharp angle with each other, while in B. 
ohliqimm their axes are in a straight line, and the common vascular bundle, 
or stele, closely resembles that of Ophioglossum Moluccanum. The stele 
of the ^primary root, however, is diarch as it is in B. Virginianum and in 
most of the Marattiales. 
The development of the cylindrical stele in the axis of the young sporo- 
phyte is essentially the same as in B. Virginianum, i.e., it is formed by the 
union of the broad leaf traces of the early leaves. 
The writer was not able to obtain the youngest stages of the sporophyte 
in Helminthostachys, but from a study of somewhat older specimens the 
conclusion was reached that the stele is formed in much the same way as 
in Botrychium.^^ 
The Marattiales 
Brebner^^ first called attention to the absence of a cauline stele in the 
young sporophyte of Danaea simplicifolia, although the writer^ ^ had shown 
in an earlier study on Marattia that there was at first a continuous procam- 
bium strand traversing the young cotyledon and primary root. Farmer's 
figures of the young sporophyte of Angiopteris^^ show the same condition. 
The most recent contribution to the subject is a paper by West^*^ who finds 
that there is no cauline stele in the young sporophyte of the Marattiaceae. 
Fig. 5. A. Vertical section of an embryo of Danaea elliptica, passing through the 
cotyledon, and showing the endogenous origin of the root, r. B. A nearly median section 
of a very young sporophyte of Marattia Douglasii, showing the young stele extending from 
the cotyledon into the root. The root apex does not show in this section. 
^® Campbell. The Eusporangiatae. 
" Brebner, loc. cit. 
^^Campbell, D, H. Observations on the development of Marattia Douglasii, Baker. 
Annals of Bot. 8: 1-20. 1894. 
Farmer, J. B. The embryogeny of Angiopteris evecta, Hoffm. Annals of Bot. 
6:265-270. 1892. 
20 West, loc. cit. 
