434 BOTANICAL GAZETTE [MAY 
two cotyledons. Looking at fig. 1 of pl. V in the Microcycas paper 
(14), and comparing it with my fig. 13, one would be puzzled to 
say which is the dicotyledon and which the monocotyledon. The 
same difficulty would arise by comparing my fig. 10 with fig. 13 
of pl. VI of the Microcycas paper. Sister HELEN ANGELA was 80 
impressed with the complete fusion of the two cotyledons that she 
called the fused structure a sheath. 
Furthermore, a consideration of the vascular connections, the 
four root poles with their extensions finding full outlet in the sheath, 
shows that this sheath represents the whole cotyledonary apparatus, 
which, historically, finds its expression in many cotyledons in 
Pinus, in two in the normal cycads and dicotyledonous angio- 
sperms, and in the sheath of monocotyledons. 
This condition seems to me almost the last proof necessary 
to demonstrate the origin of monocotyledons from dicotyledons. 
Summary 
1. The embryo sac of Cyrtanthus seems to follow the regular 
Lilium type. The endosperm is very extensive. 
2. Stomata are more numerous on the inner than on the outer 
surface of the carpel. 
3. There are three separate bundles at the midrib of each carpel 
and two at the fusion of the carpels. This arrangement is related 
to the various parts of the flower. 
4. The youngest observed stages of the embryo have the stem 
tip enveloped by a sheath with four lobes at its top. 
5. In an older embryo the sheath is differentiated into a longer 
and a shorter side, the appearance and vascular anatomy of which 
give the distinct impression of two cotyledons. 
6. Any pressure or fusion is referred to the extraordinary 
amount of endosperm. 
7. The investigation is considered a last proof of the theory of 
monocotyledony from dicotyledony. 
The author wishes to express her grateful acknowledgment 
to Dr. Cuartes J. CHAmBeRtatn for material, to Dr. Joun M- 
