382 
The Ohio Naturalist. 
[Vol. VI, No. 1, 
The development of the embryo from this stage on was not 
traced very closely but the divisions must occur rather rapidlv 
for on May 2;>rd the embryo had reached about the 12-celled 
stage (Fig. lo). On May 29th a large spherical embryo was 
present (Fig. lb). The suspensor had lengthened considerably 
and sections showed a double row of cells (Fig. lb). At this time 
the antipodals were degenerating (Fig. 17). They lie in a broad 
depression at the base of the sac which is greatly enlarged and 
filled with endosperm. The behavior of the antipodals recalls the 
condition of these cells in certain Ranunculaceae. On June bth 
the ovules had matured and were falling to the ground. The 
integument is very hard and it was found necessary to remove 
it before imbedding in paraffin. At this time the embryo was 
much larger and the two cotelydons were well developed (F'ig. 
bS). The suspensor was still ])resent but showed signs of 
degeneration. 
SUMM.\RY. 
The flowers of Sanguinaria begin to develo]) very early in 
the summer ])revious to the year in which they blossom. 
The development of the microsporocytes and microspores is 
much more ra]nd than that of the megaspores for the micro- 
spores are formed before the winter season begins. 
The ovule ])asses the winter in the megasporocyte stage and 
during March its development is very rapid while the microspore 
does not renew activity until the last of March and early April. 
Three ])arietal cells are formed and later these divide forming 
a ])arietal tissue of considerab'e size. 
The division of the megasporocyte frequently results in 
rather tyi)ical tetrads. 
The generative nucleus does not appear to divide in the 
pollen grain. 
The long resting ])eriod of the oos])here is especially 
interesting. 
RlBLIOGR.\.PHY. 
1 . Vesque, J. 
Xouvelle recherches sur le development du sac embryon- 
naire des Phanerogames Angiospermes. Ann. Sci. Nat. Bot. 
VI, 8:2bl 390. Pis! 12-21. 1S79. 
2. Str.\sburger, E. ^ 
Neue Untersuchungen uber den Befruchtungsvorgang 
bei den Phanerogamen. Jena. 1SS4. St*: 1 j 
d. Sh.\w, Ch.\rles H. 
Notes on sexual generation and the development of the 
seed coats in certain of the Papaveraceae. Bull. Tor. Bot. 
Club 31;429-4dd, PI. Id. 1904. 
