‘THE EMBRYO SAC AND EMBRYO OF STRIGA LUTEA 
MARGARET R, MICHELL 
(WITH PLATES VIIL AND IX) 
Attention lately has been drawn to Striga lutea, a semi-parasitic 
plant belonging to the Rhinanthoideae-Gerardieae (8) group of the 
Scrophulariaceae, owing to the ravages caused by it in the maize 
crops in parts of South Africa. 
The material for this investigation was obtained by Dr. H. H. 
W. Pearson in Pretoria during the autumn of the years 1912 
and 1913. : 
The ovaries were fixed in a chromacetic solution and the chief 
stain used was Haidenhain’s iron-hematoxylin. A combination of 
diamant fuchsin and light green also gave good results, and 
Flemming’s triple stain gave excellent differentiation in the embry- 
onic stages. 
Ovule and embryo sac 
There is nothing striking in the ovary. It is of the ordinary 
bilocular scrophulariaceous type, and bears a large number of 
minute anatropous ovules on the rather swollen placentae. Many 
of the ovules possess long funicles, and in some cases the funicle 
branches and bears two ovules. The fact that the length of funicle 
varies enables the plant to produce a greater number of ovules per 
unit area of placenta than it would be able to do were the funicles 
all of one length. 
The archesporium can be distinguished at an early stage before 
the integument arises. It consists of a single hypodermal cell 
which, without undergoing division, becomes directly the mega- 
spore mother cell. This is shown in fig. 1, which also shows the 
origin of the integument. The young ovules grows with great 
rapidity, and before the first division of the nucleus of the mega- 
spore mother cell, the integument is well marked and the whole 
ovule is rapidly assuming its mature anatropous form. 
The nucellus consists of one layer of cells. As development 
proceeds the cells become flattened and finally disorganized, so that 
Botanical Gazette, vol. 59] [124 
