Anatomy of the Ofihioglosseae. 391 
the first two protoxylem-elements, which in this case are 
a considerable distance apart. 
In his first paper he describes the stele of the root as 
being always monarch, though he states that he has some- 
times seen protoxylem at two opposite points : but he adds, 
‘ Thus the root in this case appears to be diarch, but it be- 
comes afterwards monarch, because the lower part of the 
phloem does not develop.’ Thus he apparently regards the 
xylem as representing a diarch plate, and one of the two 
phloem-groups as absent. The dichotomy of the root is 
described 1 by him, and the stele of the root is stated to 
become concentric before the branching, several phloem- 
elements appearing on the lower side of the xylem, and the 
two steles after the dichotomy being at first concentric. 
The above description is not very definite as to the amount 
and distribution of the phloem, and is supplemented by the 
observations of Poirault 2 , who says that the stele before 
division possesses several sieve-tubes on the lower side 3 , but 
that these are scattered and not grouped as in the normal 
phloem-mass 4 . The other details of the dichotomy need 
not be referred to here, but this occurrence of scattered sieve- 
tubes on the lower side of the xylem is quoted because the 
same thing sometimes occurs in the mother-root near the 
base of the adventitious plant, on both sides of the latter. 
It may be explained as a local development of the part of 
the phloem which is normally abortive (viz. the lower parts 
of the two phloem-masses). 
Poirault 5 describes another anomaly as occurring in roots 
of Ophioglossum vulgatum , namely, the occurrence of a second 
phloem-group, similar to the normal one, on the lower side 
of the xylem, these two phloem-groups being connected by 
a series of sieve-tubes round the ends of the xylem-mass. 
1 1. c. (earlier paper), p. 75. 
2 Poirault, Journal de Botanique, t. vi, 1892, p. 70. 
3 He writes -‘upper side’ by mistake. 
* This agrees with a figure in Rostowzew’s Russian memoir (Fig. to) repre- 
senting the young stele of a dichotomised root. 
3 Poirault, 1 . c., p. 70, and Gomptes-rendus, 1891, p. 967. 
D d 2 
