454 Mottier.— T he Embryology of some Anomalous Dicotyledons. 
base of the cotyledons. In conclusion it may be said that the embryo of 
Sanguinaria canadensis shows a well-marked, though not very pronounced, 
degree of anomaly in the development of the cotyledons, and that this 
anomalous character may persist in the embryo found in the ripe seed. 
Variations in the degree of anomaly are also to be observed. 
Stylophorum diphyllum. 
The development of the embryo of Stylophorum is similar to that 
of Sanguinaria ; consequently attention will be directed to certain features 
only. The earlier stages, in so far as they were observed, were similar 
to those of Sanguinaria. Beginning with the development of the 
cotyledons, we find that they originate in the familiar crescent-shaped 
ridge (Fig. 27, a-f). In this figure I have indicated the plerome of the 
cotyledons and hypocotyl by broken lines. After what has been said 
concerning Sanguinaria , this series of outline drawings is self-explanatory. 
It is worthy of note, moreover, that the anomaly, in so far as it is present, 
is even less pronounced in Stylophorum , the bifurcation of the crescentic 
primordium occurring earlier, and in the mature embryo the depth of 
the sinuses is almost, if not quite, equal. Not only this, but cases were 
observed (Fig. 26, a-c) in which no anomaly was present. In these we 
have before us apparently the development of a typical dicotyledonous 
form. In such a typical dicotyledonous form, however, it must be 
remembered that, as stated in a foregoing paragraph, the primordia of 
the cotyledons involve nearly the whole end of the embryo as in the 
most pronounced anomalous types (Fig. 2 6, a-b). The difference between 
Figs. 26 and 27 lies mainly in the fact that, in the former, the primordium 
bifurcates to form the two sinuses at exactly the same time, and it is 
doubtless proper to speak of primordia rather than of a single primordium ; 
but these primordia are not so distinctly isolated as one might suppose 
from the descriptions usually given of the origin of the cotyledons. In 
the nearly mature seed, although the cotyledons are relatively short, the 
embryo is much less in the form of a low broad goblet than that of 
Sanguinaria , i. e., the longitudinal axis is greater than the transverse 
(Fig. 28). The suspensor is also short. Stylophorum diphyllum may 
be regarded, therefore, as typically dicotyledonous, showing a tendency 
only to a slightly anomalous character in the formation of the cotyledons. 
Delphinium tricorne. 
We shall now follow the development of the embryo in two or 
three more species of the Ranunculaceae for comparison with Actea alba. 
Agreeing with the other species already described, the pear-shaped 
embryo of Delphinium tricorne is somewhat flattened at right angles to 
the plane of the cotyledons (Fig. 29). The first indication of the cotyle- 
