7 
the Ophioglossaceae . 
Material of these species was secured from Maine and Massachusetts. 
These species show their relation to B. ternatum by the similar form of the 
petiolar strand, the two parts of which almost meet adaxially, so that the 
form is nearly that of the letter O. From the adaxial edges break off 
the two strands which supply the fertile spike ; these may approximate, 
but do not fuse. In both fertile and sterile segments the branches of the 
vascular system arise in the manner just stated. Thus the gap left by the 
exit of branch traces in B. virginianum has disappeared in the species 
under consideration. 
Botrychium Limaria was examined by Roeper and others, who found 
the double vascular supply of the fertile spike. By soaking out and 
imbedding herbarium material, I have been able to verify the earlier 
accounts. The whole vascular system of the leaf is markedly two-sided; 
the leaf-trace splits before the leaf has become free from the stem, and the 
two halves diverge rather widely. The strands which supply the fertile 
spike and also those which supply the lobes of the leaves arise from the free 
adaxial edges of the main strands. A slight prominence on the inner side 
of the latter at the point of departure of a branch may represent a vestige 
of the ‘ lateral strand ’ described under B. ternatum. If such is the case 
B. lunaria is to be regarded as a reduced species derived from more fern¬ 
like ancestors. 
Botrychium simplex , material of which I owe to Mr. J. C. Parlin, looks 
externally like a reduced Lunaria , and its internal structure bears this out. 
Its vascular system is quite similar, but the strands are smaller, especially 
those of the sterile segment, so that those of the sterile and fertile parts are 
of about equal size. The two petiolar strands divide into adaxial and 
abaxial parts, so that the gap seen in B. virginianum has quite disappeared. 
The two strands of the fertile spike remain separate throughout their 
length. 
Certain abnormal forms of B. obliquum , Muhl., may next be considered. 
Through the great kindness of Mr. F. W. Bachelder a supply of this 
interesting material, collected in the vicinity of Manchester, New Hamp¬ 
shire, has been available for study. The external features of the specimens 
have been briefly described by Mr. Bachelder ( 1 ), and the peculiarity 
consists in the presence of two or three fertile spikes in place of one, 
or in the presence of one or more fertile pinnae among the ordinary sterile 
ones. Certain of these specimens were photographed, then soaked up and 
swelled out by means of warm dilute ammonia, and afterwards imbedded 
and cut into serial sections in the usual manner. 
In the simplest of these cases, two similar fertile spikes arise in the 
normal position (Fig. 24), diverging slightly right and left. Externally 
they appear to form a pair, and the structure corresponds to this view, for 
the petiolar strand has in transverse section the form of a U, from each 
