VOLUME XXV NUMBER 5 
IDOTANICAL (GAZETTE 
MAY 1898 
THE ORIENTATION OF THE PLANT EGG AND ITS 
ECOLOGICAL SIGNIFICANCE. 
Conway MACMILLAN. 
AS a convenient series of forms in which the embryogeny 
kes been carefully investigated one may select the Archegoniate. 
- Atumber of groups in which genuine eggs are developed thus 
All outside the limits of discussion. Among these are the 
otophy cea with such genera as Sphzroplea and Coleochete ; 
heophy ce, particularly Fucus and its allies; and the 
elie as for example Peronospora and Achlya. The 
3 — mc types of segmentation will be found to be derived 
_ “«tlain archegoniate types and will receive incidental atten- 
te » but it will be quite unnecessary to enter into an examina- 
77 the modified and often degenerate processes that succeed 
F physiological equivalent of fecundation in Rhodophycee- 
 Payco 
oo of certain important types of egg segmentation known 
al among the plants classified by Engler as Embryophyta, 
ama, 
ome 8 bryophytes the egg manifests in the Hepatice all the 
... “*gmentation that are retained in the higher order. 
i. ett will be unnecessary to give any special account for 
nec. Essentially all Musci present segmentations that are 
301 
